of: irq: Report individual failures in of_irq_init()

of: irq: Report individual failures in of_irq_init()

New pr_err(), a copy of preceeding pr_debug(), faciliates debugging.

This change was inspired by a long lasting debugging of the
octeon_irq_init_ciu() which fails completely silently and leaves the
interrupt controller half-way configured which in turn had very non-obvious
effects.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Link: https://lore.kernel.org/r/20220907121629.54330-1-alexander.sverdlin@nokia.com
Signed-off-by: Rob Herring <robh@kernel.org>