arm64: dts: mt2712-evb: Fix vproc fixed regulators unit names

Update the names to regulator-vproc-buck{0,1} to fix unit_addres_vs_reg
warnings for those.

Fixes: f75dd8bd ("arm64: dts: mediatek: add mt2712 cpufreq related device nodes")
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221013152212.416661-6-angelogioacchino.delregno@collabora.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>