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/board/freescale/b4860qds/b4860qds.c b/board/freescale/b4860qds/b4860qds.c
index 33cd4b4..24efe77 100644
--- a/board/freescale/b4860qds/b4860qds.c
+++ b/board/freescale/b4860qds/b4860qds.c
@@ -7,6 +7,7 @@
 #include <command.h>
 #include <env.h>
 #include <i2c.h>
+#include <irq_func.h>
 #include <netdev.h>
 #include <linux/compiler.h>
 #include <asm/mmu.h>