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/sh/lib/zimageboot.c b/arch/sh/lib/zimageboot.c
index 93933b7..602776a 100644
--- a/arch/sh/lib/zimageboot.c
+++ b/arch/sh/lib/zimageboot.c
@@ -10,6 +10,7 @@
  */
 
 #include <common.h>
+#include <irq_func.h>
 #include <asm/io.h>
 #include <asm/zimage.h>