common: Move enable/disable_interrupts out of common.h

Move these two functions into the irq_funcs.h header file. Also move
interrupt_handler_t as this is used by the irq_install_handler() function.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arc/lib/bootm.c b/arch/arc/lib/bootm.c
index 254e028..d38c18e 100644
--- a/arch/arc/lib/bootm.c
+++ b/arch/arc/lib/bootm.c
@@ -3,6 +3,7 @@
  * Copyright (C) 2013-2014 Synopsys, Inc. All rights reserved.
  */
 
+#include <irq_func.h>
 #include <asm/cache.h>
 #include <common.h>