Use data format as unspecified for voice

For voice usecases, while opening the slimbus
slave ports, currently data format LPCM(1) is used.
SB master uses data format as unspecified(0). SB master's
data format overwrites the slave side configuration.
In the rare cases, this mismatch may lead to pop sound
in SCO Tx(BT FW->LPASS) at the very beginning when
voice is switched from speaker/handset to BT from call UI.
To fix this, use the data format as unspecified during
opening of the slimbus slave ports for voice cases.

CRs-Fixed: 2710472
Change-Id: Ia9b1d23cbf04d1b8056d7b7f7c84a066437e1682
Signed-off-by: Satish Kodishala <skodisha@codeaurora.org>