The current GIC configuration scheme is designed to support only one
specific type and version of GIC (i.e. GIC-400 that implements the
GICv2 interface).
This commit adds a set of GIC version configuration symbols that can
be selected by the SoC configuration to specify which version of GIC
interface is implemented in the SoC.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
