[qca-nss-drv] Enable NSS offload for PPTP GRE sequence number handling

1. Added new stats counter PPTP exception types
2. Added an API to post PPTP GRE packets to firmware
3. Fixed the PPTP stats

Change-Id: Icabc345459a457eb8f9f6b43be94a8f7e6622671
Signed-off-by: Shyam Sunder <ssunde@codeaurora.org>
5 files changed