gpio: Request interrupts after IRQ is initialized

Commit 5467801 ("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: 5467801 ("gpio: Restrict usage of GPIO chip irq members before initialization")
Link: https://lore.kernel.org/linux-gpio/BL1PR12MB51577A77F000A008AA694675E2EF9@BL1PR12MB5157.namprd12.prod.outlook.com/
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 <mario.limonciello@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Reviewed-by: Shreeya Patel <shreeya.patel@collabora.com>
Tested-By: Samuel Čavoj <samuel@cavoj.net>
Tested-By: lukeluk498@gmail.com Link:
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-and-tested-by: Takashi Iwai <tiwai@suse.de>
Cc: Shreeya Patel <shreeya.patel@collabora.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: superm1

drivers/gpio/gpiolib.c

@@ -1601,8 +1601,6 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc,
 
 	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
@@ -1612,6 +1610,8 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc,
 
 	gc->irq.initialized = true;
 
+	acpi_gpiochip_request_interrupts(gc);
+
 	return 0;
 }