[MIPS] vmlinux.lds.S: Handle note sections

Store any note sections after the exception tables like the other
architectures do.  This is required for .note.gnu.build-id emitted from
binutils 2.18 onwards if nothing else.

Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>