audio: aptX: don't set bit-width explicitly

While finding the output profile for the aptX HD
A2DP the bit-width set to 24, but this leads to using
default app-type if there is no matching profile
for current audio format with 24 bit-width.

Don't set bit-width to 24 explicitly in case of
aptX HD.

CRs-Fixed: 2011277
Change-Id: If28ff26fb8e242d20ba0a98ff229fe278f1ec299