ARM: dts: msm: Fix the clocks for Venus VMEM on msmcobalt

Enable the VMEM clock dependencies for msmcobalt.
While at it, cleanup the clock names specified before.

Change-Id: I8a7556626035139e67ec3d722b60b6cf60232f6b
Signed-off-by: Chinmay Sawarkar <chinmays@codeaurora.org>