hexagon: select GENERIC_IRQ_PROBE instead of redefining it

Select GENERIC_IRQ_PROBE, as the other architectures do.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Brian Cain <bcain@quicinc.com>