I have noticed some of our interrupt handlers use both dev and
dev_priv while they could get away with only dev_priv in the
huge majority of cases.

Tidying that up had a cascading effect on changing functions
prototypes, so relatively big churn factor, but I think it is
for the better.

For example even where changes cascade out of i915_irq.c, for
functions prefixed with intel_, genX_ or <plat>_, it makes more
sense to take dev_priv directly anyway.

This allows us to eliminate local variables and intermixed usage
of dev and dev_priv where only one is good enough.

End result is shrinkage of both source and the resulting binary.

i915.ko:

 - .text         000b0899
 + .text         000b0619

Or if we look at the Gen8 display irq chain:

 -00000000000006ad t gen8_irq_handler
 +0000000000000663 t gen8_irq_handler
   -0000000000000028 T intel_opregion_asle_intr
   +0000000000000024 T intel_opregion_asle_intr
   -000000000000008c t ilk_hpd_irq_handler
   +000000000000007f t ilk_hpd_irq_handler
   -0000000000000116 T intel_check_page_flip
   +0000000000000112 T intel_check_page_flip
   -000000000000011a T intel_prepare_page_flip
   +0000000000000119 T intel_prepare_page_flip
   -0000000000000014 T intel_finish_page_flip_plane
   +0000000000000013 T intel_finish_page_flip_plane
   -0000000000000053 t hsw_pipe_crc_irq_handler
   +000000000000004c t hsw_pipe_crc_irq_handler
   -000000000000022e t cpt_irq_handler
   +0000000000000213 t cpt_irq_handler

So small shrinkage but it is all fast paths so doesn't harm.

Situation is similar in other interrupt handlers as well.

v2: Tidy intel_queue_rps_boost_for_request as well. (Chris Wilson)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>