pinctrl: core: Don't use "proxy" headers

Update header inclusions to follow IWYU (Include What You Use)
principle.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>

drivers/pinctrl/core.c

@@ -24,7 +24,7 @@
 #include <linux/seq_file.h>
 #include <linux/slab.h>
 
-#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/gpio/driver.h>
 
 #include <linux/pinctrl/consumer.h>