msm: venc: Fix encoder buffer size calculations

Encoder internal buffer size calculations has a few bugs.
Change the macros based on firmware discussions:
- Add extra 512 bytes for scratch calculation
- Adjust vpp/vpss/lambda lut size for scratch1 calculation
- Always use max number of vpp pipes for AVC/HEVC scratch1
- Use an extra reference frame for scratch2 calculation
- Remove recalculation of meta stride/height in scratch2
  calculation.

CRs-Fixed: 2368458
Change-Id: I0a3cad8e645934d9a32aaca682a0d65900ab4b86
Signed-off-by: Vaibhav Deshu Venkatesh <vdeshuve@codeaurora.org>