This commit intends to stop grepping CPU type in
arch/m68k/cpu/mcf52x2/config.mk.

Move the CPU type config options from include/configs/*.h
to arch/m68k/Kconfig and refactor the CPU flags select in
arch/m68k/cpu/mcf52x2/config.mk.
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Cc: Alison Wang <alison.wang@freescale.com>
Cc: Angelo Dureghello <angelo@sysam.it>