msm: ipa: fix ipa data path crash

Crash is seen during WLAN bi-directional high throughput
use-case (APPS <-> WLAN STA). Work being queued from SPS
TX completion ISR was extracted from SPS callback argument
and was not valid is some corner-cases. Use a static work
item instead.

Change-Id: Iab801cb23951ce6c5cc7c6e2285974999434fafe
Signed-off-by: Ravi Gummadidala <rgummadi@codeaurora.org>