pinctrl: sprd: Allow the SPRD pinctrl driver building into a module

Change the config to 'tristate' and export some symbols needed by modules
to allow the Spreadtrum pinctrl driver building into a module.
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Link: https://lore.kernel.org/r/d7239f3c7379e402f665fc8927f635ac56691380.1582776447.git.baolin.wang7@gmail.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sprd/Kconfig

@@ -4,7 +4,7 @@
 #
 
 config PINCTRL_SPRD
-	bool "Spreadtrum pinctrl driver"
+	tristate "Spreadtrum pinctrl driver"
 	depends on OF
 	depends on ARCH_SPRD || COMPILE_TEST
 	select PINMUX
@@ -15,7 +15,7 @@ config PINCTRL_SPRD
 	  Say Y here to enable Spreadtrum pinctrl driver
 
 config PINCTRL_SPRD_SC9860
-	bool "Spreadtrum SC9860 pinctrl driver"
-	depends on PINCTRL_SPRD
+	tristate "Spreadtrum SC9860 pinctrl driver"
+	select PINCTRL_SPRD
 	help
 	  Say Y here to enable Spreadtrum SC9860 pinctrl driver

drivers/pinctrl/sprd/pinctrl-sprd.c

@@ -1090,6 +1090,7 @@ int sprd_pinctrl_core_probe(struct platform_device *pdev,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(sprd_pinctrl_core_probe);
 
 int sprd_pinctrl_remove(struct platform_device *pdev)
 {
@@ -1098,6 +1099,7 @@ int sprd_pinctrl_remove(struct platform_device *pdev)
 	pinctrl_unregister(sprd_pctl->pctl);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(sprd_pinctrl_remove);
 
 void sprd_pinctrl_shutdown(struct platform_device *pdev)
 {
@@ -1112,6 +1114,7 @@ void sprd_pinctrl_shutdown(struct platform_device *pdev)
 		return;
 	pinctrl_select_state(pinctl, state);
 }
+EXPORT_SYMBOL_GPL(sprd_pinctrl_shutdown);
 
 MODULE_DESCRIPTION("SPREADTRUM Pin Controller Driver");
 MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>");