Add missing support for LP8764 PMIC in the probe().

Issue detected with v6.10-rc1 (and reproduced with 6.10-rc2) using a TI
J7200 EVM board.

tps6594-pinctrl tps6594-pinctrl.8.auto: error -EINVAL:
  Couldn't register gpio_regmap driver
tps6594-pinctrl tps6594-pinctrl.8.auto: probe with driver tps6594-pinctrl
  failed with error -22

Fixes: 20882971 (pinctrl: pinctrl-tps6594: Add TPS65224 PMIC pinctrl and GPIO)
Signed-off-by: Thomas Richard <thomas.richard@bootlin.com>
Link: https://lore.kernel.org/r/20240603082110.2104977-1-thomas.richard@bootlin.comSigned-off-by: Linus Walleij <linus.walleij@linaro.org>