defconfig: sa8155: enable QMI for CNSS2

CNSS2 platform driver uses QMI framework to communicate with WLAN
firmware. It sends and receives boot handshake messages to WLAN
firmware, which includes hardware and software capabilities and
configurations. It also sends WLAN on/off control message to
firmware over QMI channel.

CRs-Fixed: 2381673
Change-Id: Ic070cf142c7601f4d458be161833f4e9a34c5c63
Signed-off-by: Yu Wang <yyuwang@codeaurora.org>