Revert "gpio: Restrict usage of GPIO chip irq members before initialization"

This reverts commit 0912cf02.

It breaks the kernel abi so revert it for now.  We will add it back
later at the next kabi update.

Bug: 161946584
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ic05524e1d76a349bf55d12d3b571114483ed7d1b