msm: ipa: create debugfs root during pre-init

Create debugfs root for IPA during driver pre-init since the ethernet
offload subsystem init need to create sub-directories under it.

CRs-Fixed: 2304918
Change-Id: Id2f2e43ae23d0cacb8c4d2bafd219cffbaf50774
Signed-off-by: Jinesh K. Jayakumar <jineshk@codeaurora.org>