UPSTREAM: ath10k: Update rx descriptor for WCN3990 target

WCN3990 rx descriptor uses different offset of msdu start, msdu end,
ppdu end, rx pkt end and rx frag info.
To accommodate different offsets, define respective fields in
rx descriptor of WCN3990 target.

Signed-off-by: Govind Singh <govinds@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
Git-commit: e3def6f7ddf88636febb12e1e3e86387a4ce5452
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/ath.git


Change-Id: I17fc4a4585c9cea14651b3c1024e4070cefbb050
Signed-off-by: Dundi Raviteja <dundi@codeaurora.org>