MIPS: Make local arrays with CL_SIZE static __initdata

Since commit 22242681

 ("MIPS: Extend
COMMAND_LINE_SIZE"), CL_SIZE is 4096 and local array variables with this
size will cause an build failure with default CONFIG_FRAME_WARN settings.

Although current users of such array variables are all early bootstrap
code and not likely to cause real stack overflow (thread_info corruption),
it is preferable to  to declare these arrays static with __initdata.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>