resource: add define macro for register address resources

DEFINE_RES_ macros have been created for the commonly used resource types,
but not IORESOURCE_REG. Add the macro so it can be used in a similar manner
to all other resource types.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20220905162132.2943088-7-colin.foster@in-advantage.com

include/linux/ioport.h

@@ -172,6 +172,11 @@ enum {
 #define DEFINE_RES_MEM(_start, _size)					\
 	DEFINE_RES_MEM_NAMED((_start), (_size), NULL)
 
+#define DEFINE_RES_REG_NAMED(_start, _size, _name)			\
+	DEFINE_RES_NAMED((_start), (_size), (_name), IORESOURCE_REG)
+#define DEFINE_RES_REG(_start, _size)					\
+	DEFINE_RES_REG_NAMED((_start), (_size), NULL)
+
 #define DEFINE_RES_IRQ_NAMED(_irq, _name)				\
 	DEFINE_RES_NAMED((_irq), 1, (_name), IORESOURCE_IRQ)
 #define DEFINE_RES_IRQ(_irq)						\