msm_serial_hs: Setting DESC_DONE and INT flags for BAM mode

UART driver queue transfer request to BAM and expect rx callback completion
from BAM for the queued descriptor. With current UART BAM configurations
for rx path, it seen that BAM Hardware did not set EOT flag to the
descriptor processed and hence did not generate any End of Transfer
interrupt. Thus, UART driver did not receive any callback from SPS driver
for that descriptor. This results in issue of Rx stall with UART.

Hence fixing the issue by using option DESC_DONE with sps_config and INT
flag option for queued BAM descriptor. With these configurations, UART
receives rx callback completion for queued transfer request from BAM
and data transfer happens normal without any rx stall with UART.

CRs-Fixed: 473902
Change-Id: I7482d20b4bd0d7d04fe5d1400eff568bc53b1e53
Signed-off-by: Saket Saurabh <ssaurabh@codeaurora.org>