kernel: backport commit reverting genirq patch causing regressions

kernel: backport commit reverting genirq patch causing regressions

Switching from kernel 4.4.120 to 4.4.124 introduced a regression in
the genirq code. It was caused by a commit 9d0273bb1c4b6 ("genirq: Use
irqd_get_trigger_type to compare the trigger type for shared IRQs").

On bcm53xx it breaks serial console and results in a flood of:
[   22.078829] genirq: Flags mismatch irq 18. 00000080 (serial) vs. 00000080 (gpio)
[   22.086432] genirq: Flags mismatch irq 18. 00000080 (serial) vs. 00000080 (gpio)
[   22.601150] genirq: Flags mismatch irq 18. 00000080 (serial) vs. 00000080 (gpio)
[   22.608845] genirq: Flags mismatch irq 18. 00000080 (serial) vs. 00000080 (gpio)

Later in the upstream "linux-4.4.y" branch that commit was reverted and
it was followed by a 4.4.126 release. Until we switch from 4.4.124 to
4.4.126 (or newer), let's backport that reverting commit.

Fixes: bed0ee7cbfaa5 ("Kernel: bump 4.4 to 4.4.124 for 17.01")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>