MIPS: Replace all usages of CL_SIZE by COMMAND_LINE_SIZE

The MIPS-specific macro CL_SIZE is merely aliasing the macro
COMMAND_LINE_SIZE. Other architectures use the latter; also,
COMMAND_LINE_SIZE is documented in kernel-parameters.txt, so
let's use it, and remove the alias.

Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>