pinctrl: fix PINCTRL_SPPCTL=m

The PINCTRL_SPPCTL option is defined as a tristate in Kconfig, and the help text suggests that the user can build it as a module by setting to 'm'.

However, it cannot currently be set to 'm', because SOC_SP7021, the only platform that supports it, is a bool option that uses 'select' on it. Also, the SP7021 requires this driver to be built in, in order to boot.

Change the tristate to bool and fix the help text.

Tested on linux-next-2026-09-14 on a LTPP3G2 board.

This impossible tristate was detected by kconfirm, a static analysis tool for Kconfig, by Julian Braha <[email protected]>.

---
 drivers/pinctrl/sunplus/Kconfig | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

index 69f82590f6d2..aa9435d023d8 100644
@@ -4,8 +4,8 @@
 #
 
 config PINCTRL_SPPCTL
-	tristate "Sunplus SP7021 PinMux and GPIO driver"
-	depends on SOC_SP7021
+	bool "Sunplus SP7021 PinMux and GPIO driver"
+	depends on SOC_SP7021 || COMPILE_TEST
 	depends on OF && HAS_IOMEM
 	select GENERIC_PINCTRL_GROUPS
 	select GENERIC_PINMUX_FUNCTIONS

@@ -16,6 +16,4 @@ config PINCTRL_SPPCTL
 	help
 	  Say Y here to support Sunplus SP7021 pinmux controller.
 	  This driver requires the pinctrl framework.
-	  GPIO is provided by the same driver.
-	  To compile this driver as a module, choose M here.
-	  The module will be called sppinctrl.
+	  This driver also provides GPIO.

I applied this patch as a nonurgent fix.

Yours,
Linus Walleij