msm: mdss: fix SMP allocation size when using BWC

When using Bandwidth Compression, the size for Shared Memory Pool blocks
allocation is calculated within helper function mdss_mdp_get_rau_strides
and includes the lines to be fetched in RAU, there is no need to again
account for these while reserving SMP blocks. Also this function should
not include the meta data within RAU, this is only used to decompress the
stream from memory but is dropped when storing stream in SMP.

CRs-Fixed: 492113
Change-Id: I188736994b9038f74d13dc587d16a7b9445a7fbe
Signed-off-by: Adrian Salido-Moreno <adrianm@codeaurora.org>