kbuild: sync with Linux Kernel v3.15-rc1

This commit imports Kbuild-related updates
from v3.14 to v3.15-rc1.

 - commit 3d3d6b8474204b6819688c9800774d52d370a538
    kbuild: LLVMLinux: Adapt warnings for compilation with clang
 - commit 61163efae02040f66a95c8ed17f4407951ba58fa
    kbuild: LLVMLinux: Add Kbuild support for building kernel with Clang
 - commit 79192ca8ebd9a25c583aa46024a250fef1e7766f
    scripts: objdiff: detect object code changes between two commits
 - commit 1c9e70a55b088d97a59241744fe459409d0c3582
    kbuild: create a build directory automatically for out-of-tree build
 - commit a03fcb50e816a69acffb13b5e56db75063aeba8a
    kbuild: remove redundant '.*.cmd' pattern from make distclean
 - commit 13338935f1574a2dcd1c891461b0dcc42f8cff42
    kbuild: move "quote" to Kbuild.include to be consistent
 - commit bfdfaeae500a3b194b73b01e92a8034791a58b7f
    kbuild: specify build_docproc as a phony target
 - commit f4d4ffc03efc864645b990e1d579bbe1b8e358a4
    kbuild: dtbs_install: new make target
 - commit 1e64ff42ea3d8d2fc8aa71f9717b3c1cb6c2f893
    Kbuild, lto: Disable LTO for asm-offsets.c
 - commit ccbef1674a1579842c7dbdf554efca85d2cd245a
    Kbuild, lto: add ld-version and ld-ifversion macros
 - commit ae63b2d7bdd9bd66b88843be0daf8e37d8f0b574
    scripts/tags.sh: Ignore *.mod.c
 - commit e36aaea28972c57a32a3ba5365e61633739719b9
    kbuild: Fix silent builds with make-4

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
kbuild: docbook: sync with Linux Kernel v3.15-rc1

This commit imports DocBook-related updates
from v3.14 to v3.15-rc1.

 - commit ec3fadd64b9940baa2a369bf978e8561837db3f5
    kbuild: docbook: use $(obj) and $(src) rather than specific path
 - commit 100da4c0150c97ce34d4d3b38bf2f5449b05ae4f
    kbuild: docbook: specify KERNELDOC dependency correctly
 - commit 6f89b9c1d6b29eaa600ac4a8ac1314b0d06f15e3
    kbuild: docbook: include cmd files more simply
 - commit ac6d662a95a6989d83b259ccf8ec01dd7903af73
    doc: Add "*.svg" to DocBook/.gitignore
 - commit 832919bfcf0cfd75767c68b0c61f7cf48be860a8
    DocBook: Make mandocs parallel-safe
 - commit c4d79a4799719f2b0cd354ee498aad605730c97e
    work around xmlto bug in htmldocs

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
kbuild: add user-supplied CPPFLAGS, AFLAGS and CFLAGS

Like Linux Kernel, this commit provides environment variables
KCPPFLAGS, KAFLAGS and KCFLAGS, which are useful to pass
additional options.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
bootm: set max decompression size for LZO

The LZO decompressor wasn't initializing the maximum output size, which
meant it would fail to decompress most of the time.

Reported-by: Matthias Weißer <weisserm@arcor.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Matthias Weißer <weisserm@arcor.de>
Acked-by: Simon Glass <sjg@chromium.org>
e1000: remove redundant assignment

Signed-off-by: David Mueller <d.mueller@elsoft.ch>
Joe Hershberger <joe.hershberger@gmail.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
buildman: make output dir configurable

Add an option to specify the output directory to override the
default path '../'. This is useful for building in a ramdisk.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
build: Use filechk rules to create and update u-boot.lds

Prior to this patch, the top-level linker script u-boot.lds
used a simple $(call if_changed) check when generated.
That mechanism misses cases where a possible include file
change induces a change in the u-boot.lds too.

This patch converts it to a stronger check using ($call filechk)
that will also notice differences in file contents and
will catch changes due to pre-processing as well.

Signed-off-by: Jon Loeliger <jon.loeliger@oracle.com>