[PATCH 2/3] of: OF_IRQ: select IRQ_DOMAIN instead of depending on it

[Randy Dunlap <rdunlap@infradead.org>]

IRQ_DOMAIN is a hidden (not user visible) symbol. Users cannot set
it directly thru "make *config", so drivers should select it instead
of depending on it if they need it.
Relying on it being set for a dependency is risky.

Consistently using "select" or "depends on" can also help reduce
Kconfig circular dependency issues.

Therefore, change OF_IRQ's use of "depends on" to "select".

This patch reduces one Kconfig circular dependency in
drivers/mux/Kconfig when MUX_MMIO attempts to select REGMAP, which
that driver needs (but does not completely resolve that issue). [1]

[1] https://lore.kernel.org/lkml/20230210115625.GA30942@pengutronix.de/

Fixes: 63c60e3a6dc3 ("of: OF_IRQ should depend on IRQ_DOMAIN")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Peter Rosin <peda@axentia.se>
---
I have a similar patch (should be a series) for REGMAP.

 drivers/of/Kconfig |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff -- a/drivers/of/Kconfig b/drivers/of/Kconfig
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -68,7 +68,8 @@ config OF_ADDRESS
 
 config OF_IRQ
 	def_bool y
-	depends on !SPARC && IRQ_DOMAIN
+	depends on !SPARC
+	select IRQ_DOMAIN
 
 config OF_RESERVED_MEM
 	def_bool OF_EARLY_FLATTREE