When qp goes less than 10, all I16x16 mode evaluations
are disabled and I4x4 evaluations are enabled irrespective
of preset. This will ensure that the residual will not
exceed the supported range of entropy
Minimum Qp cannot be set less than 4 now. When QP goes lesser,
the residual may exceed the supported range even with I4x4 enabled.
Change-Id: I25b404fcd9c9e9dbdd77679280968635ee047eb3