pinctrl: stm32: select IRQ_DOMAIN_HIERARCHY instead of depends on

Drivers that need IRQ_DOMAIN_HIERARCHY should "select" it, but
drivers/pinctrl/stm32/Kconfig is the only exception that uses
"depends on" syntax.  This prevents GPIO drivers from select'ing
IRQ_DOMAIN_HIERARCHY.

For example, if I add "select IRQ_DOMAIN_HIERARCHY" to GPIO_XGENE_SB,
I get the following recursive dependency error.

drivers/gpio/Kconfig:13:error: recursive dependency detected!
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/gpio/Kconfig:13:	symbol GPIOLIB is selected by PINCTRL_STM32
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/pinctrl/stm32/Kconfig:3:	symbol PINCTRL_STM32 is selected by PINCTRL_STM32F429
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/pinctrl/stm32/Kconfig:11:	symbol PINCTRL_STM32F429 depends on IRQ_DOMAIN_HIERARCHY
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
kernel/irq/Kconfig:67:	symbol IRQ_DOMAIN_HIERARCHY is selected by GPIO_XGENE_SB
For a resolution refer to Documentation/kbuild/kconfig-language.txt
subsection "Kconfig recursive dependency limitations"
drivers/gpio/Kconfig:502:	symbol GPIO_XGENE_SB depends on GPIOLIB

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Tested-by: Alexandre TORGUE <alexandre.torgue@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>