arm64: dts: qcom: sm8350-mtp: add regulator names

Add the property "regulator-names" to the regulators as given in
schematics so that it is easier to understand the regulators being used

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20210204170907.63545-7-vkoul@kernel.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>