gpio: xlp: Fix build errors from Netlogic XLP removal

Commit ea708ac5 ("gpio: xlp: Remove Netlogic XLP variants") has
build errors with CONFIG_ACPI:

drivers/gpio/gpio-xlp.c:300:23: error: 'GPIO_VARIANT_VULCAN' undeclared here (not in a function)

and !CONFIG_OF:

drivers/gpio/gpio-xlp.c:267:11: error: 'struct gpio_chip' has no member named 'of_node'

Fix these errors.

Fixes: ea708ac5

 ("gpio: xlp: Remove Netlogic XLP variants")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>