ARM: ks8695: __arch_virt_to_dma type handling

__arch_virt_to_dma expects a virtual address pointer, but
the ks8695 implementation of this macro treats it as an
integer. Adding a type cast avoids hundreds of identical
warning messages.

Without this patch, building acs5k_defconfig results in:

arch/arm/include/asm/dma-mapping.h: In function 'virt_to_dma':
arch/arm/include/asm/dma-mapping.h:60:2: warning: passing argument 1 of '__virt_to_phys' makes integer from pointer without a cast [enabled by default]
arch/arm/include/asm/memory.h:172:60: note: expected 'long unsigned int' but argument is of type 'void *'
In file included from include/linux/dma-mapping.h:73:0,
                 from include/linux/skbuff.h:33,
                 from security/commoncap.c:21:

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Cc: Daniel Silverstone <dsilvers@simtec.co.uk>
Cc: Ben Dooks <ben-linux@fluff.org>