usb: gadget: bam_data: Wait for BAM reset only on A2 BAM

Previous change 'usb: gadget: Fix race condition in connect/disconnect'
introduced a bug which adds unnecessary delay waiting for bam
reset completion after usb cable disconnection. BAM reset completion
is not needed for IPA bam type. Fix it by waiting for bam reset only
for A2 bam.

Change-Id: I491e5ff561b226711ec80d281a3c7dbb91a91f96
CRs-Fixed: 503808
Signed-off-by: Bar Weiner <bweiner@codeaurora.org>