COMMAND_LINE_SIZE and CONFIG_FRAME_WARN

[Atsushi Nemoto <anemo@mba.ocn.ne.jp>]

Recently COMMAND_LINE_SIZE (CL_SIZE) was extended to 4096 from 512.
(commit 22242681 "MIPS: Extend COMMAND_LINE_SIZE")

This cause warning if something like buf[CL_SIZE] was declared as a
local variable, for example in prom_init_cmdline() on some platforms.

And since many Makefiles in arch/mips enables -Werror, this cause
build failure.

How can we avoid this error?

- do not use local array? (but dynamic allocation cannot be used in
  such an early stage.  static array?)
- are there any way to disable -Wframe-larger-than for the file or function?
- make COMMAND_LINE_SIZE customizable?
- use non default CONFIG_FRAME_WARN?

Any comments or suggestions?
---
Atsushi Nemoto