ARM: dts: msm: Update venus clock frequencies on msmcobalt v2

Aligns the frequencies to the FMAX values defined by clock
driver for venus on msmcobalt v2 target. Also link these
frequencies to appropriate load values and imem ab levels.

CRs-Fixed: 1053136
Change-Id: I755d1ad62de97ded55f73148e1a56bc3afafc03b
Signed-off-by: Chinmay Sawarkar <chinmays@codeaurora.org>