LinuxKPI: add devm_request_irq()

Add devm_request_irq() needed by a driver. Turns out all we need
is a wrapper with the right arguments to lkpi_request_irq().

Reviewed by: emaste
Differential Revision: https://reviews.freebsd.org/D37217

(cherry picked from commit 6e8d6761312e92227a87e0e07b51f89ff81a24b3)