misc: microchip: pci1xxxx: fix dependency issues in building the pci1xxxx's aux bus driver.

build errors and warnings listed below and reported by kernel
test robot <lkp@intel.com> on the char-misc-next branch are
fixed in this add-on patch.

errors:
  ERROR: modpost: "auxiliary_device_init" [drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.ko] undefined!
  ERROR: modpost: "__auxiliary_device_add" [drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.ko] undefined!
  ERROR: modpost: "auxiliary_driver_unregister" [drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gpio.ko] undefined!
  ERROR: modpost: "__auxiliary_driver_register" [drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gpio.ko] undefined!
  ia64-linux-ld: drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gp.o: in function `gp_aux_bus_probe.part.0':
  mchp_pci1xxxx_gp.c:(.text+0x342): undefined reference to `auxiliary_device_init'
  ia64-linux-ld: mchp_pci1xxxx_gp.c:(.text+0x392): undefined reference to `__auxiliary_device_add'
  ia64-linux-ld: mchp_pci1xxxx_gp.c:(.text+0x5c2): undefined reference to `auxiliary_device_init'
  ia64-linux-ld: mchp_pci1xxxx_gp.c:(.text+0x612): undefined reference to `__auxiliary_device_add'
  ia64-linux-ld: drivers/misc/mchp_pci1xxxx/mchp_pci1xxxx_gpio.o: in function `pci1xxxx_gpio_driver_init':
  mchp_pci1xxxx_gpio.c:(.init.text+0x42): undefined reference to `__auxiliary_driver_register'

warnings:
  unmet direct dependencies detected for GPIOLIB_IRQCHIP when selected by GP_PCI1XXXX

Fixes: 393fc2f594 ("misc: microchip: pci1xxxx: load auxiliary bus driver for the PIO function in the multi-function endpoint of pci1xxxx device.")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
Link: https://lore.kernel.org/r/20220906124951.696776-1-kumaravel.thiagarajan@microchip.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/mchp_pci1xxxx/Kconfig

@@ -1,7 +1,9 @@
 config GP_PCI1XXXX
        tristate "Microchip PCI1XXXX PCIe to GPIO Expander + OTP/EEPROM manager"
-       depends on PCI	
+       depends on PCI
+       depends on GPIOLIB
        select GPIOLIB_IRQCHIP
+       select AUXILIARY_BUS
        help
          PCI1XXXX is a PCIe GEN 3 switch with one of the endpoints having
          multiple functions and one of the functions is a GPIO controller