MIPS: Loongson: Split the implementation of prom and setup parts

This patch split the old initilization and setup implementation to
several file, one file one logic function.

the other main changes include:

	1. as the script/checkpatch.pl suggests, use strict_strtol instead
	of simple_strtol in arch/mips/lemote/lm2e/cmdline.c

	2. use the existed macros in asm/mips-boards/bonito64.h as the
	arguments of set_io_port_base() and remove the un-needed ones in
	asm/mach-lemote/pci.h

Signed-off-by: Wu Zhangjin <wuzj@lemote.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>