scripts/genpinctrl: Add SDMMC pins configuration

Add config for SDMMC signals generation.
Not available on F1 series.

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>

scripts/genpinctrl/stm32-pinctrl-config.yaml

@@ -181,6 +181,11 @@
   match: "^I2S\\d+_SD$"
   mode: alternate
 
+- name: SDMMC
+  match: "^SDMMC\\d+_(?:CK)?(?:CKIN)?(?:CDIR)?(?:CMD)?(?:D\\d+)?(?:D0DIR)?(?:D123DIR)?$"
+  mode: alternate
+  slew-rate: very-high-speed
+
 - name: SPI_MISO
   match: "^SPI\\d+_MISO$"
   mode: alternate