This change had added interrupt control routines for vrc4173.

Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Yoichi Yuasa <yuasa@hh.iij4u.or.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>