ARM: relocation: don't undef CONFIG_SYS_ARM_WITHOUT_RELOC

There were some #undef's of CONFIG_SYS_ARM_WITHOUT_RELOC added to a few board
configs as part of the arm relocation series; but these are not needed now as we
do not #undef what is not #defined in the first place.

Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
CC: Heiko Schocher <hs@denx.de>