spi: ppc4xx: Avoid returning 0 when failed to parse and map IRQ

spi: ppc4xx: Avoid returning 0 when failed to parse and map IRQ

[ Upstream commit 7781f1d120fec8624fc654eda900fc8748262082 ]

0 is incorrect error code when failed to parse and map IRQ.
Replace OF specific old API for IRQ retrieval with a generic
one to fix this issue.

Fixes: 0f245463b01e ("spi: ppc4xx: handle irq_of_parse_and_map() errors")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20240814144525.2648450-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>