gpio: thunderx: select IRQ_DOMAIN_HIERARCHY instead of depends on

IRQ_DOMAIN_HIERARCHY is not user-configurable, but supposed to be
selected by drivers that need IRQ domain hierarchy support.

GPIO_THUNDERX is the only user of "depends on IRQ_DOMAIN_HIERARCHY".
This means, we can not enable GPIO_THUNDERX unless other drivers
select IRQ_DOMAIN_HIERARCHY elsewhere.  This is odd.  Flip the logic.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/gpio/Kconfig

@@ -453,7 +453,8 @@ config GPIO_TS4800
 config GPIO_THUNDERX
 	tristate "Cavium ThunderX/OCTEON-TX GPIO"
 	depends on ARCH_THUNDER || (64BIT && COMPILE_TEST)
-	depends on PCI_MSI && IRQ_DOMAIN_HIERARCHY
+	depends on PCI_MSI
+	select IRQ_DOMAIN_HIERARCHY
 	select IRQ_FASTEOI_HIERARCHY_HANDLERS
 	help
 	  Say yes here to support the on-chip GPIO lines on the ThunderX