post_proc: Fix improper datatype of EQ preset band level value

unsigned int causes negative band level turn out to be extreme large
value, which results in EQ works abnormally due to unexpected parameter
sent.

Change-Id: I81120c604f4e9f23b25d5a45a7b0294fea63d207
CRs-Fixed: 696825
hal: Add support for several DB8074 specific audio devices

Fix DB8074 VoIP issue and the recording use case.

Change-Id: I99aaf21474d210ce33881ab32b95821352608139