As discussed on linux-arm-kernel, we want to avoid
relative includes for the arch/arm/*omap* shared code:

http://www.spinics.net/lists/linux-omap/msg80520.html

Let's add plat/debug-devices.h for debug_card_init()
to fix the relative includes.

Note that drivers must not use this header as it will
break build for omap2+ CONFIG_MULTIPLATFORM builds.

Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

This can be local to mach-omap2.
Signed-off-by: NTony Lindgren <tony@atomide.com>

debug_card_init() function resides in the plat/board.h file.
Move it to a separate header file under plat/ so the board.h file can be
removed.
Signed-off-by: NIgor Grinberg <grinberg@compulab.co.il>
Signed-off-by: NTony Lindgren <tony@atomide.com>