MIPS: Malta: Fix include paths in malta-amon.c

On linux-queue, malta doesn't build after the include file relocation.
This should fix it.

There some occurrences of 'asm-mips' in the comments of quite a few
files, but this is the only place I found it in any code.

Signed-off-by: David Daney <ddaney@avtrex.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>