st/va: force to submit two consecutive single jobs

st/va: force to submit two consecutive single jobs

The gop_size in rate control is the budget window for internal rate
control calculation, and shouldn't always equal to idr period. Define
a coefficient to let budget window contains a number of idr period for
proper rate control calculation. Adjust the number of i/p frame remaining
accordingly.

v2: fixed regression issues introduced by previous version

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=98005
Signed-off-by: Boyuan Zhang <boyuan.zhang@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>