ARM: 6275/1: ux500: don't use writeb() in uncompress.h

Don't use writeb() in uncompress.h, to avoid the following build errors
when the "Add barriers to the I/O accessors" series is applied.  Use
__raw_writeb() instead.

arch/arm/boot/compressed/misc.o: In function `putc':
arch/arm/mach-ux500/include/mach/uncompress.h:41:
undefined reference to `outer_cache'

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>