ARM: dts: msm: update and enable clock_rpmh device for SDM855

Update the device tree node for clock_rpmh to specify a
functional compatible string instead of dummycc.  This
ensures that consumer requests modify clock hardware state.

Also remove the bi_tcxo clock from the gcc clock driver since
it will now be registered by the rpmh clock driver.

Change-Id: I6dd31956cf6fc3a5c7e7c405102fed1a88608be1
Signed-off-by: David Collins <collinsd@codeaurora.org>