msm:vidc: provide support to raise video clks to turbo mode.

This change provides support to raise video clks to turbo mode for mpeg4
clips with high number of slices. The firmware performance degrades if
the number of slices is more than 10. Without this fix, we see lot of
frame drops happening, causing a freeze effect.

Change-Id: I79d0b9a438f73d87384b9e03761a65b9de3c9fc7
CRs-Fixed: 358615
Signed-off-by: Mohan Kumar Gubbihalli Lachma Naik <mgubbi@codeaurora.org>