gpio: Request interrupts after IRQ is initialized

Commit 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members
before initialization") attempted to fix a race condition that lead to a
NULL pointer, but in the process caused a regression for _AEI/_EVT
declared GPIOs.

This manifests in messages showing deferred probing while trying to
allocate IRQs like so:

amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x0000 to IRQ, err -517
amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x002C to IRQ, err -517
amd_gpio AMDI0030:00: Failed to translate GPIO pin 0x003D to IRQ, err -517
[ .. more of the same .. ]

The code for walking _AEI doesn't handle deferred probing and so this
leads to non-functional GPIO interrupts.

Fix this issue by moving the call to `acpi_gpiochip_request_interrupts`
to occur after gc->irc.initialized is set.

Fixes: 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before initialization")
Link: https://lore.kernel.org/linux-gpio/[e-mail]/
Link: https://bugzilla.suse.com/show_bug.cgi?id=1198697
Link: https://bugzilla.kernel.org/show_bug.cgi?id=215850
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1979
Link: https://gitlab.freedesktop.org/drm/amd/-/issues/1976
Reported-by: Mario Limonciello <[e-mail]>
Signed-off-by: Mario Limonciello <[e-mail]>
Reviewed-by: Shreeya Patel <[e-mail]>
Tested-By: Samuel Čavoj <[e-mail]>
Tested-By: [e-mail] Link:
Reviewed-by: Andy Shevchenko <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Reviewed-and-tested-by: Takashi Iwai <[e-mail]>
Cc: Shreeya Patel <[e-mail]>
Cc: [e-mail]
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/gpio/gpiolib.c

···
 
 	gpiochip_set_irq_hooks(gc);
 
-	acpi_gpiochip_request_interrupts(gc);
-
 	/*
 	 * Using barrier() here to prevent compiler from reordering
 	 * gc->irq.initialized before initialization of above
···
 	barrier();
 
 	gc->irq.initialized = true;
+
+	acpi_gpiochip_request_interrupts(gc);
 
 	return 0;
 }