decoder: h264: fix initialization of RefPicLists for multiple slices.

The initialization of reference picture lists (8.2.4.2) applies to all
slices. So, the RefPicList0/1 lists need to be constructed prior to
each slice submission to the HW decoder.

This fixes decoding of video sequences where frames are encoded with
multiple slices of different types, e.g. 4 slices in this order I, P,
I, and P. More precisely, CABAST3_Sony_E and CABASTBR3_Sony_B.

Signed-off-by: Zhong Cong <congx.zhong@intel.com>
decoder: h264: fix long-term reference picture marking process.

Fix reference picture marking process with memory_management_control_op
set to 3 and 6, i.e. assign LongTermFrameIdx to a short-term reference
picture, or the current picture.

This fixes decoding of FRExt_MMCO4_Sony_B.

Signed-off-by: Zhong Cong <congx.zhong@intel.com>
decoder: h264: unified variable type to prevent the occurrence of abnormal variable contrast.

Signed-off-by: Zhong Cong <congx.zhong@intel.com>