kbuild,tools: generate wrapper C sources automatically by Makefile

There are many source files shared between U-boot image and tools.
Instead of adding a lot of dummy wrapper files that just include
the corresponding file in lib/ or common/ directory,
Makefile should automatically generate them.

The original inspiration for this came from
scripts/Makefile.asm-generic of Linux Kernel.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Acked-by: Simon Glass <sjg@chromium.org>
Tested-by: Simon Glass <sjg@chromium.org>
Series-to: uboot
Series-cc: sjg
Series-cc: Charles Manning <cdhmanning@gmail.com>
Series-cc: Gerhard Sittig <gsi@denx.de>
Series-version: 2
Series-changes: 2
  - Rebase on commit 3e1fa221
kbuild: export HOSTCXX and HOSTCXXFLAGS

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
kbuild: collect useful commands into scripts/Makefile.lib
aaaa
move blackfin specific objcopy rules
kbuild: move drivers/input to drivers/Makefile
include/configs: Do not use $(BOARDDIR)
zynq: disable -Wstrict-prototypes option for ps7_init.c

The files ps7_init.c and ps7_init.h are supposed to be generated by
hw projects such as Vivado, PlanAhead and then to be copied into
board/xilinx/zynq directory.

But some prototypes in them cause annoying warning messages:

  CC      spl/board/xilinx/zynq/ps7_init.o
In file included from board/xilinx/zynq/ps7_init.c:50:0:
board/xilinx/zynq/ps7_init.h:137:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.h:138:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.h:139:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.h:145:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.c:12602:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.c:12723:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.c:12742:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.c:12761:1: warning: function declaration isn't a prototype [-Wstrict-prototypes]
board/xilinx/zynq/ps7_init.c:12854:6: warning: function declaration isn't a prototype [-Wstrict-prototypes]

The prototypes should be

  int ps7_init(void);
  int ps7_post_config(void);
  int ps7_debug(void);

rather than

  int ps7_init();
  int ps7_post_config();
  int ps7_debug();

We do not want to be bothered because of automatically generated files.
But we cannot touch the external projects for now.
What we can do is to disable -Wstrict-prototypes for ps7_init.c

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Series-to: uboot
Series-version: 2
Series-changes: 2
   No change in code. Some changes in git-log
  - Fix a typo:  s/causes/cause/
  - Add Tested-by credit
boards.cfg: move more boards to Orphan

Chan-Taek Park <c-park@ti.com>
Inderpal Singh <inderpal.singh@linaro.org>
Matt Waddel <matt.waddel@linaro.org>

are invalid email addresses.