phy: mediatek: phy-mtk-hdmi: add regulator dependency

The driver no longer builds when regulator support is unavailable:

arm-linux-gnueabi-ld: drivers/phy/mediatek/phy-mtk-hdmi.o: in function `mtk_hdmi_phy_register_regulators':
phy-mtk-hdmi.c:(.text.unlikely+0x3e): undefined reference to `devm_regulator_register'
arm-linux-gnueabi-ld: drivers/phy/mediatek/phy-mtk-hdmi-mt8195.o: in function `mtk_hdmi_phy_pwr5v_is_enabled':
phy-mtk-hdmi-mt8195.c:(.text+0x326): undefined reference to `rdev_get_drvdata'
arm-linux-gnueabi-ld: drivers/phy/mediatek/phy-mtk-hdmi-mt8195.o: in function `mtk_hdmi_phy_pwr5v_disable':
phy-mtk-hdmi-mt8195.c:(.text+0x346): undefined reference to `rdev_get_drvdata'
arm-linux-gnueabi-ld: drivers/phy/mediatek/phy-mtk-hdmi-mt8195.o: in function `mtk_hdmi_phy_pwr5v_enable':

Fixes: 49393b2 ("phy: mediatek: phy-mtk-hdmi: Register PHY provided regulator")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20241213083056.2596499-1-arnd@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/mediatek/Kconfig

@@ -65,6 +65,7 @@ config PHY_MTK_HDMI
 	depends on ARCH_MEDIATEK || COMPILE_TEST
 	depends on COMMON_CLK
 	depends on OF
+	depends on REGULATOR
 	select GENERIC_PHY
 	help
 	  Support HDMI PHY for Mediatek SoCs.