[ARM] Fix jornada720 build errors

kernel/built-in.o: In function `pm_suspend':
utsname_sysctl.c:(.text+0x23008): multiple definition of `pm_suspend'
arch/arm/mach-sa1100/built-in.o:arch/arm/mach-sa1100/sleep.S:(.text+0xf68): first defined here
arm-linux-ld: Warning: size of symbol `pm_suspend' changed from 20 in arch/arm/mach-sa1100/built-in.o to 44 in kernel/built-in.o

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>