soc/tegra: pmc: Rename DT props to make its length < 32

soc/tegra: pmc: Rename DT props to make its length < 32

Rename some of DT properties to make its length < 32 character
to meet ePAPR specs.

Still keep the older property to have backward compatibility.
Properties are:
  nvidia,wait-before-start-bus-clear-us -> nvidia,wait-start-bus-clear-us
  nvidia,core-power-req-active-high -> nvidia,core-pwr-req-active-high

Bug 200347832

Change-Id: I866bda9c7353a384eed950ead9b78835efa1dc8d
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1564325
Reviewed-by: svc-mobile-coverity <svc-mobile-coverity@nvidia.com>
Reviewed-by: Shardar Mohammed <smohammed@nvidia.com>
Reviewed-by: svccoveritychecker <svccoveritychecker@nvidia.com>
GVS: Gerrit_Virtual_Submit
(cherry picked from commit 592da8e7352fbc3f30a080a51940bcd7241121b5)