The OpenFirmware part of this driver is uncompilable on SPARC due to it's
dependance on several PPC specific functions.

Restricting this to PPC to prevent these build errors:
  CC      drivers/video/mb862xx/mb862xxfb.o
drivers/video/mb862xx/mb862xxfb.c: In function 'of_platform_mb862xx_probe':
drivers/video/mb862xx/mb862xxfb.c:559: error: implicit declaration of function 'of_address_to_resource'
drivers/video/mb862xx/mb862xxfb.c:575: error: 'NO_IRQ' undeclared (first use in this function)
drivers/video/mb862xx/mb862xxfb.c:575: error: (Each undeclared identifier is reported only once
drivers/video/mb862xx/mb862xxfb.c:575: error: for each function it appears in.)

This was found using randconfig builds.
Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Anatolij Gustschin <agust@denx.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>