msm_serial_hs_lite: Remove kernel panic

Do not use panic() when tx operation timeouts, which
leads to kernel panic causing crash.
Instead of panic which effects the driver stability,
resetting the transmitter will work good and keep
transmitting the data.

CRs-Fixed: 578961
Change-Id: I3449cf152cecb1d557b24f770e4fb71e1f2bde00
Signed-off-by: Dilip Kota <c_dkota@codeaurora.org>