Convert GSI_MASK_IRQ and GSI_UNMASK_IRQ to inline functions.
v1 -> v2:
After changing GSI_MASK_IRQ and GSI_UNMASK_IRQ from MACROs to functions,
'gsi_(mask|unmask)_irq' are the exposed APIs and 'irq_gsi_mask_unmask'
becomes internal.
In order to reflect this change,
- change 'irq_gsi_mask_unmask' as internal function in ioapic.c
- declare 'gsi_(mask|unmask)_irq' in ioapic.h
- define 'gsi_(mask|unmask)_irq' in ioapic.c
Tracked-On: #861
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>