drm/mediatek: stop selecting foreign drivers

drm/mediatek: stop selecting foreign drivers

The PHY portion of the mediatek hdmi driver was originally part of
the driver it self and later split out into drivers/phy, which a
'select' to keep the prior behavior.

However, this leads to build failures when the PHY driver cannot
be built:

WARNING: unmet direct dependencies detected for PHY_MTK_HDMI
  Depends on [n]: (ARCH_MEDIATEK || COMPILE_TEST [=y]) && COMMON_CLK [=y] && OF [=y] && REGULATOR [=n]
  Selected by [m]:
  - DRM_MEDIATEK_HDMI [=m] && HAS_IOMEM [=y] && DRM [=m] && DRM_MEDIATEK [=m]
ERROR: modpost: "devm_regulator_register" [drivers/phy/mediatek/phy-mtk-hdmi-drv.ko] undefined!
ERROR: modpost: "rdev_get_drvdata" [drivers/phy/mediatek/phy-mtk-hdmi-drv.ko] undefined!

The best option here is to just not select the phy driver and leave that
up to the defconfig. Do the same for the other PHY and memory drivers
selected here as well for consistency.

Fixes: a481bf2f0ca4 ("drm/mediatek: Separate mtk_hdmi_phy to an independent module")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20241218085837.2670434-1-arnd@kernel.org/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>