[PATCH] pinctrl: bm1880: add missing select GENERIC_PINCONF

[Benjamin Boortz <bennib@mailbox.org>]

drivers/pinctrl/pinctrl-bm1880.c initialises its pinconf_ops with
.is_generic = true, but that field is only present when
CONFIG_GENERIC_PINCONF is enabled (guarded by #ifdef in pinconf.h).
The Kconfig entry for PINCTRL_BM1880 never selects GENERIC_PINCONF,
so any config that enables CONFIG_PINCTRL_BM1880=y without
CONFIG_GENERIC_PINCONF=y fails to compile:

  drivers/pinctrl/pinctrl-bm1880.c:1288:10: error: 'const struct pinconf_ops' has no member named 'is_generic'

Found by randconfig testing on arm64; tinyconfig reproducer below.
Add the missing select to fix the build.

Fixes: 49bd61ebce5f ("pinctrl: Add pinconf support for BM1880 SoC")
Cc: stable@vger.kernel.org
Signed-off-by: Benjamin Boortz <bennib@mailbox.org>

---
Reproducer (tinyconfig, arm64, without patch):

  make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- tinyconfig
  scripts/config --enable CONFIG_PINCTRL
  scripts/config --enable CONFIG_PINCTRL_BM1880
  make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- olddefconfig
  make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- \
      drivers/pinctrl/pinctrl-bm1880.o
---
 drivers/pinctrl/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/pinctrl/Kconfig b/drivers/pinctrl/Kconfig
index 23ea76dc6261..eda54aa5fde6 100644
--- a/drivers/pinctrl/Kconfig
+++ b/drivers/pinctrl/Kconfig
@@ -166,6 +166,7 @@ config PINCTRL_BM1880
 	depends on OF && (ARCH_BITMAIN || COMPILE_TEST)
 	default ARCH_BITMAIN
 	select PINMUX
+	select GENERIC_PINCONF
 	help
 	  Pinctrl driver for Bitmain BM1880 SoC.
 
-- 
2.55.0