pinctrl: stmfx: Fix pin configuration issue

pin-controller pin's name must be equal to pin's name used in device
tree with "pins" DT property.

Issue detected on stm32mp157c-ev1 board with goodix touchscreen.
In DT, the goodix's pin is declared in DT with the node:

        goodix_pins: goodix {
		pins = "gpio14";
		bias-pull-down;
	};

Whereas in stmfx pin-controller driver, pin's name are equal to
"stmfx_gpioxx" where xx is the pin number.
This lead to not configure stmfx's pins at probe because pins is
identified by its name (see pinctrl_pin_name_to_selector() in
pinctrl-generic.c) and stmfx pin "gpio14" can't be found.

To fix this issue, come back to the original stmfx pin's name.

Revert "pinctrl: stmfx: update pin name"

This reverts commit 38d30cdcd65c73eeefac5efa328ad444a53b77dd.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Tested-by: Patrick DELAUNAY <patrick.delaunay@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
diff --git a/drivers/pinctrl/pinctrl-stmfx.c b/drivers/pinctrl/pinctrl-stmfx.c
index 7cf08db..b4baf35 100644
--- a/drivers/pinctrl/pinctrl-stmfx.c
+++ b/drivers/pinctrl/pinctrl-stmfx.c
@@ -343,8 +343,8 @@
 }
 
 /*
- * STMFX pins[15:0] are called "stmfx_gpio[15:0]"
- * and STMFX pins[23:16] are called "stmfx_agpio[7:0]"
+ * STMFX pins[15:0] are called "gpio[15:0]"
+ * and STMFX pins[23:16] are called "agpio[7:0]"
  */
 #define MAX_PIN_NAME_LEN 7
 static char pin_name[MAX_PIN_NAME_LEN];
@@ -352,9 +352,9 @@
 					      unsigned int selector)
 {
 	if (selector < STMFX_MAX_GPIO)
-		snprintf(pin_name, MAX_PIN_NAME_LEN, "stmfx_gpio%u", selector);
+		snprintf(pin_name, MAX_PIN_NAME_LEN, "gpio%u", selector);
 	else
-		snprintf(pin_name, MAX_PIN_NAME_LEN, "stmfx_agpio%u", selector - 16);
+		snprintf(pin_name, MAX_PIN_NAME_LEN, "agpio%u", selector - 16);
 	return pin_name;
 }