MIPS: Cleanup and Fixup of compressed kernel support

 o Remove the .initrd section.  The initrd section was already handled
   when vmlinux was linked.
 o Discard .MIPS.options, .options, .pdr, .reginfo, .comment and .note
   sections.  If .MIPS.options is not removed, kernels compiled with gcc
   3.4.6 will not boot.
 o Clean up the file format.
 o Remove several other unneeded sections.

Tested with GCC 3.4.6 and 4.4.1 with and without initrd.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/785/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>