asoc: wsa884x: fix device tree parsing issue for sys gain
System gain is miscalculated due to incorrect parsing of
device tree property. Correct the parsing logic of the
system gain device tree property.
Change-Id: I8c9c5198a139a69c2d5d9520a071123261b0581f
Signed-off-by: Phani Kumar Uppalapati <[email protected]>