pinctrl: renesas: r8a7796: Add missing bias for PRESET# pin

R-Car Gen3 Hardware Manual Errata for Rev. 0.52 of Nov 30, 2016, added
the configuration bit for bias pull-down control for the PRESET# pin on
R-Car M3-W.  Add driver support for controlling pull-down on this pin.

Fixes: 2d40bd24 ("pinctrl: sh-pfc: r8a7796: Add bias pinconf support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/c479de5b3f235c2f7d5faea9e7e08e6fccb135df.1619785375.git.geert+renesas@glider.be

drivers/pinctrl/renesas/pfc-r8a7796.c

@@ -67,6 +67,7 @@
 	PIN_NOGP_CFG(QSPI1_MOSI_IO0, "QSPI1_MOSI_IO0", fn, CFG_FLAGS),	\
 	PIN_NOGP_CFG(QSPI1_SPCLK, "QSPI1_SPCLK", fn, CFG_FLAGS),	\
 	PIN_NOGP_CFG(QSPI1_SSL, "QSPI1_SSL", fn, CFG_FLAGS),		\
+	PIN_NOGP_CFG(PRESET_N, "PRESET#", fn, SH_PFC_PIN_CFG_PULL_DOWN),\
 	PIN_NOGP_CFG(RPC_INT_N, "RPC_INT#", fn, CFG_FLAGS),		\
 	PIN_NOGP_CFG(RPC_RESET_N, "RPC_RESET#", fn, CFG_FLAGS),		\
 	PIN_NOGP_CFG(RPC_WP_N, "RPC_WP#", fn, CFG_FLAGS),		\
@@ -6218,7 +6219,7 @@ static const struct pinmux_bias_reg pinmux_bias_regs[] = {
 		[ 4] = RCAR_GP_PIN(6, 29),	/* USB30_OVC */
 		[ 5] = RCAR_GP_PIN(6, 30),	/* GP6_30 */
 		[ 6] = RCAR_GP_PIN(6, 31),	/* GP6_31 */
-		[ 7] = SH_PFC_PIN_NONE,
+		[ 7] = PIN_PRESET_N,		/* PRESET# */
 		[ 8] = SH_PFC_PIN_NONE,
 		[ 9] = SH_PFC_PIN_NONE,
 		[10] = SH_PFC_PIN_NONE,