BACKPORT: block: Add ioprio to block_rq tracepoint

Sometimes we need to track the processing order of requests with
ioprio set. So the ioprio of request can be useful information.

Example：

block_rq_insert: 8,0 RA 16384 () 6500840 + 32 be,0,6 [binder:815_3]
block_rq_issue: 8,0 RA 16384 () 6500840 + 32 be,0,6 [binder:815_3]
block_rq_complete: 8,0 RA () 6500840 + 32 be,0,6 [0]

Bug: 353608803

Signed-off-by: Dongliang Cui <dongliang.cui@unisoc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit aa6ff4eb)
[dongliang.cui: Resolved minor conflict in include/trace/events/block.h]

Change-Id: I8fa32c7a24296533bf3f01e2b6b9afffb6a322f4
Signed-off-by: dongliang.cui <dongliang.cui@unisoc.com>