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/include/exports.h b/include/exports.h
index 8899622..35f4632 100644
--- a/include/exports.h
+++ b/include/exports.h
@@ -9,6 +9,8 @@
 #include <phy_interface.h>
 #endif
 
+#include <irq_func.h>
+
 struct spi_slave;
 
 /* These are declarations of exported functions available in C code */