pinctrl: add a group-specific hog macro

To create elegant tables for pinmux hogs on the PXA MMP platform,
we need this hog macro that can specify both function and group in
one go.

Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

include/linux/pinctrl/machine.h

@@ -73,6 +73,15 @@ struct pinmux_map {
 	{ .name = a, .ctrl_dev_name = b, .function = c, \
 	  .hog_on_boot = true }
 
+/*
+ * Convenience macro to map a system function onto a certain pinctrl device
+ * using a specified group, to be hogged by the pinmux core until the system
+ * shuts down.
+ */
+#define PINMUX_MAP_SYS_HOG_GROUP(a, b, c, d)		\
+	{ .name = a, .ctrl_dev_name = b, .function = c, .group = d, \
+	  .hog_on_boot = true }
+
 #ifdef CONFIG_PINMUX
 
 extern int pinmux_register_mappings(struct pinmux_map const *map,