arm64: dts: mediatek: mt8195-cherry: Assign sram supply to MFG1 pd

Add a phandle to the MT8195_POWER_DOMAIN_MFG1 power domain and
assign the GPU SRAM (vsram_others) supply to that in mt8195-cherry:
this allows to keep the sram powered up while the GPU is used.

This means that it's now possible to remove the regulator-always-on
property from the mt6359_vsram_others_ldo_reg vreg, so that it will
be switched on and off during suspend.

Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>