msm: ipa: Fix reading the VLAN parameters

When IPA_FW is loaded via bootloader, ipa post initialization is
complete even before ipa3_write is executed. As a result
when ipa3_write is called with VLAN parameters, VLAN
info is not updated and VLAN offload fails. Fix reading the
VLAN parameters even if post initialization is complete.

Change-Id: I6f61e0ef4bfa9787b5b5d68bb323d69c443e9645
Signed-off-by: Chaitanya Pratapa <cpratapa@codeaurora.org>