pinctrl: bcm2835: Allow building driver as a module

Update the pinctrl-bcm2835 driver to support being built as as a module
by converting it to a module_platform_driver() with the appropriate
module license, authors and description.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Link: https://lore.kernel.org/r/20211019221127.1953001-1-f.fainelli@gmail.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/bcm/Kconfig

@@ -18,7 +18,7 @@ config PINCTRL_BCM281XX
 	  framework.  GPIO is provided by a separate GPIO driver.
 
 config PINCTRL_BCM2835
-	bool "Broadcom BCM2835 GPIO (with PINCONF) driver"
+	tristate "Broadcom BCM2835 GPIO (with PINCONF) driver"
 	depends on OF && (ARCH_BCM2835 || ARCH_BRCMSTB || COMPILE_TEST)
 	select PINMUX
 	select PINCONF

drivers/pinctrl/bcm/pinctrl-bcm2835.c

@@ -20,6 +20,7 @@
 #include <linux/irqdesc.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
+#include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
@@ -1332,4 +1333,10 @@ static struct platform_driver bcm2835_pinctrl_driver = {
 		.suppress_bind_attrs = true,
 	},
 };
-builtin_platform_driver(bcm2835_pinctrl_driver);
+module_platform_driver(bcm2835_pinctrl_driver);
+
+MODULE_AUTHOR("Chris Boot");
+MODULE_AUTHOR("Simon Arlott");
+MODULE_AUTHOR("Stephen Warren");
+MODULE_DESCRIPTION("Broadcom BCM2835/2711 pinctrl and GPIO driver");
+MODULE_LICENSE("GPL");