CHROMIUM: camx: remove cam_irq_controller_enable_irq()

cam_irq_controller_enable_irq() is not used.

UPSTREAM-TASK=b:274966069
BUG=none
TEST=compile tested for strongbad
TEST=CCA on coachz

Change-Id: Ic95200bd0808c1725defd4fd2eeea0e3fa1717a9
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/5829322


Reviewed-by: Ricardo Ribalda <ribalda@chromium.org>
Signed-off-by: Hubert Mazur <hmazur@google.com>