USB: bam: Enable RAM12, RAM13 only for QDSS data & descriptor fifo

Currently for QDSS<->USB usecase, DWC3 core internal memory
(RAM11, RAM12, RAM13) is used for data & descriptor fifos. A data
fifo of 8KB size is enough for achieving maximum QDSS performance
instead of 16KB size. Hence enable only RAM12, RAM13 for QDSS<->USB
usecase so that remaining RAM10, RAM11 can be used for TX endpoint's
fifo allocation. This enables more fifo allocation for TX endpoints,
which will allow double buffering and results in better throughput
improvement.

CRs-Fixed: 532070
Change-Id: I7637bda9520b92537b9297f30d6003d2b6ceccf7
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>