[PATCH] uml: add asm/irqflags.h

From: Jeff Dike <jdike@addtoit.com>

Add an empty asm/irqflags.h, which seems to satisfy the lock validator enough
that UML builds.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>