qcacld-3.0: correct the path for qca-wifi-host-cmn in Kbuild
From qcacld30-hl_git.bb/qcacld30-ll_git.bb, qca-wifi-host-cmn
is in the same directory with qcacld-3.0(<src_root>/wlan/),
so correct the path for it in Kbuild.
Change-Id: I5c552d2f89cd7b6832c37d6785cfc5a0d00c795d
CRs-Fixed: 2005755