uboot-imx

MIPS: ath79: Use mach_cpu_init instead of arch_cpu_init

In order to prepare for MIPS arch code making use of arch_cpu_init in a
later patch, stop using it from ath79 SoC code & instead use the new
mach_cpu_init which is provided for this purpose.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>