kvmtool: replace GIC specific IRQ type #defines

We had GIC specific defines for the IRQ type identifiers in kvmtool.
But in fact the specification of being a level or edge interrupt
is quite generic, with the GIC binding using the generic Linux
defines.
So lets replace the GIC specific #defines in favour of the more
general names copied from Linux' include/linux/irq.h.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>