msm: vidc: Fix split mode buffer issues

When split mode is enabled, HW is erroring out due to mismatch
in buffer size and count. Fix the same issue in driver.

CRs-Fixed: 2037218
Change-Id: Iad9c545c8809861c8e1688efc17229d605f6b27d
Signed-off-by: Praneeth Paladugu <ppaladug@codeaurora.org>