[PATCH] Make hvc_console.c compile on non-powerpc: Remove NO_IRQ

Paulus preferred this over #defining NO_IRQ in the file, since that's
0 for powerpc anyway.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>