Patch from Deepak Saxena

Other than interrupt masking purposes, this API is only used when
configuring interrupt lines and this patch moves that functionality
directly into the ixp4xx_set_irq_type() implementation as board level
PCI code should not need to worry about those details.
Signed-off-by: NDeepak Saxena <dsaxena@plexity.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>