linux/rwlock.h is a no-no for direct inclusion. This remains unnoticed
when building against mainline due to prior inclusion of the correct
header, linux/spinlock.h, but breaks over the PREEMPT-RT kernel.
Would have likely been caught earlier by maintainer reviews if the
driver was developed upstream.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Change-Id: Ibc98c9017895e8991633ea4fe23171b507537525