pinctrl: sh-pfc: r8a7796: Rename EtherAVB "mdc" pin group to "mdio"

On other Renesas SoCs, the pin group for the MDIO bus is named "mdio"
instead of "mdc".  Fix the inconsistency, while retaining backwards
compatibility with old DTBs using a pin group alias.

Fixes: 4139703 ("pinctrl: sh-pfc: r8a7796: Add group for AVB MDIO and MII pins")
Fixes: 9c99a63 ("pinctrl: sh-pfc: r8a7796: Add EtherAVB pins, groups and functions")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

drivers/pinctrl/sh-pfc/pfc-r8a7796.c

@@ -1717,11 +1717,11 @@ static const unsigned int avb_phy_int_pins[] = {
 static const unsigned int avb_phy_int_mux[] = {
 	AVB_PHY_INT_MARK,
 };
-static const unsigned int avb_mdc_pins[] = {
+static const unsigned int avb_mdio_pins[] = {
 	/* AVB_MDC, AVB_MDIO */
 	RCAR_GP_PIN(2, 9), PIN_NUMBER('A', 9),
 };
-static const unsigned int avb_mdc_mux[] = {
+static const unsigned int avb_mdio_mux[] = {
 	AVB_MDC_MARK, AVB_MDIO_MARK,
 };
 static const unsigned int avb_mii_pins[] = {
@@ -4311,7 +4311,8 @@ static const struct sh_pfc_pin_group pinmux_groups[] = {
 	SH_PFC_PIN_GROUP(avb_link),
 	SH_PFC_PIN_GROUP(avb_magic),
 	SH_PFC_PIN_GROUP(avb_phy_int),
-	SH_PFC_PIN_GROUP(avb_mdc),
+	SH_PFC_PIN_GROUP_ALIAS(avb_mdc, avb_mdio),	/* Deprecated */
+	SH_PFC_PIN_GROUP(avb_mdio),
 	SH_PFC_PIN_GROUP(avb_mii),
 	SH_PFC_PIN_GROUP(avb_avtp_pps),
 	SH_PFC_PIN_GROUP(avb_avtp_match_a),
@@ -4656,7 +4657,8 @@ static const char * const avb_groups[] = {
 	"avb_link",
 	"avb_magic",
 	"avb_phy_int",
-	"avb_mdc",
+	"avb_mdc",	/* Deprecated, please use "avb_mdio" instead */
+	"avb_mdio",
 	"avb_mii",
 	"avb_avtp_pps",
 	"avb_avtp_match_a",