ASoC: WCD9310: Correct differential speaker support for Tabla 1.x

Negative signal from RX3(connected to LO1) can go to Rx4(connected
to LO2). Negative signal from RX5(connected to LO3) can go to
Rx6(connected to LO4). So for differential mode LO1/LO2 are considered
one channel and L03/LO4 are considered as another channel.

Change-Id: Icf58525662d6886e34478467b1590e8cb3f04806
CRs-fixed: 306448
Signed-off-by: Kiran Kandi <kkandi@codeaurora.org>