msm: vidc: Change kona vpu_ver to iris2

Kona specific functions are classified under vpu_ver
IRIS2. Other minor fixes include, improved logs, corrected typos
and use correct variable to indicate clock scaling support.

CRs-Fixed: 2373463
Change-Id: I876bb54b4e12106d08b570ae55a22672ef559670
Signed-off-by: Chinmay Sawarkar <chinmays@codeaurora.org>