octeontx2-pf: Use default max_active works instead of one

commit c4cc3b894c7c8b1be839c8d5675c5af8347c795c from
git@git.assembla.com:cavium/WindRiver.linux.git

Only one execution context for the workqueue used for PF and
VFs mailbox communication is incorrect since multiple works are
queued simultaneously by all the VFs and PF link UP messages.
Hence use default number of execution contexts by passing zero
as max_active to alloc_workqueue function. With this fix in place,
modify UP messages also to wait until completion.

Fixes: bd847bf31e8b ("octeontx2-pf: Add support for PF/VF mbox communication")
Change-Id: Ie55567a1b6a2da52f4cb19741198043d13791f4e
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Reviewed-on: https://sj1git1.cavium.com/c/IP/SW/kernel/linux/+/115018


Tested-by: sa_ip-sw-jenkins <sa_ip-sw-jenkins@marvell.com>
Reviewed-by: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Signed-off-by: Ruiqiang Hao <Ruiqiang.Hao@windriver.com>