ARM: ep93xx: Fix build error due to 'SZ_32M' undeclared

Include linux/sizes.h to fix below build errors:

  CC      arch/arm/mach-ep93xx/adssphere.o
arch/arm/mach-ep93xx/adssphere.c: In function 'adssphere_init_machine':
arch/arm/mach-ep93xx/adssphere.c:32:49: error: 'SZ_32M' undeclared (first use in this function)
arch/arm/mach-ep93xx/adssphere.c:32:49: note: each undeclared identifier is reported only once for each function it appears in
make[1]: *** [arch/arm/mach-ep93xx/adssphere.o] Error 1
make: *** [arch/arm/mach-ep93xx] Error 2

  CC      arch/arm/mach-ep93xx/gesbc9312.o
arch/arm/mach-ep93xx/gesbc9312.c: In function 'gesbc9312_init_machine':
arch/arm/mach-ep93xx/gesbc9312.c:32:49: error: 'SZ_8M' undeclared (first use in this function)
arch/arm/mach-ep93xx/gesbc9312.c:32:49: note: each undeclared identifier is reported only once for each function it appears in
make[1]: *** [arch/arm/mach-ep93xx/gesbc9312.o] Error 1
make: *** [arch/arm/mach-ep93xx] Error 2

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Ryan Mallon <rmallon@gmail.com>