dm: README: recommend u-boot.dtb to try driver-model on sandbox

To enjoy driver-model on sandbox, using device tree is recommended.
While we are here, change sandbox_config to sandbox_defconfig too.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
sh: move -m options to arch/sh/config.mk

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
dm: do not check dm_root before searching in uclass_root

The function uclass_find() looks for a uclass in the linked
list of gd->uclass_root; gd->dm_root has nothing to do with
gd->uclass_root.  Remove this confusing code.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
dm: minor coding style fixes
kconfig: add CONFIG_CROSS_COMPILE

Copy from Linux Kernel (with a few adjustments in comments).
kbuild: collect useful commands into scripts/Makefile.lib
include/configs: Do not use $(BOARDDIR)
patman,buildman: remove redundant readlines() method

In Python, file objects can be used directly in iterators
without readlines() method.

The behavior is the same but it generally saves memory
without readlines().

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
patman: use raw strings for regular expression

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
buildman: Do not parse git aliase file
consolidate undefined macros
scripts/mailmapper: add overwrite option
buildman: Do not search under non-existing toolchain directories

The function glob.glob(pathname) is useful for expanding '*' in the
pathname. But it can be used even if '*' is not contained in the
pathname. In this case, glob.glob() returns an empty list if the given
pathname does not exist.

It means glob.glob is useful for all cases, not only for expanding '*'
but also for ignoring non-existing pathname.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
buildman: remove unnecessay sanity check

The confitonal statement "if config_fname:" is redundant
because ConfigParser.read() always succeeds even if an empty
string is given to its argument.

Besides, 'config_fname' always contains a non-empty string.
The variable 'config_fname', if empty, is set to '$HOME/.buildman'
at the previous line.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
buildman: improve readability of toolchain check
patman, buildman: avoid using magic numbers in code

When changing the foreground color, '+30' is a magic number.
Put it into the BRIGHT_START and NORMAL_START macros.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
errno.h: do not include <asm-generic/errno.h> directly

Including <asm-generic/foo.h> directly is wrong.

<asm-generic/foo.h> is supposed to be included from
arch/${ARCH}/include/asm/foo.h to provide the default
of arch-specific macros/functions.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
dm: i2c: support 10bit addressing in I2C uclass layer

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>