[NEUS7920-133][9610] wlbt: Use single threaded wq in hip4 bh

[NEUS7920-133][9610] wlbt: Use single threaded wq in hip4 bh

We have recently (A50 project) observed several issues to schedule
hip4_wq work, most likely because the kernel is blocked and is not
granting us CPU cycles.

In current implementation the work is added in the systemwq. Systemwq
might be easily affected by other subsystems adding batch works that
might eventually block our pending work.

In order to avoid using systemwq, the patch creates a new singlethread
workqueue and adds the non-napi process context bottom half works in there.

Change-Id: I0cc69779aa91c26777f00a2e7b1cd840336f553d
SCSC-Bug-Id: SSB-50566
Signed-off-by: Albert Cano <a.canocamps@samsung.com>