Updated Redistributor base calculation to allow for the fact that
GICv4 has 2 additional 64KB frames (for VLPI and a reserved frame).
The code now tests the VLPIS bit in the GIC Redistributor Type
Register (GICR_TYPER) and calculates the Redistributor granularity
accordingly.
The code changes are:
GICR_TYPER register fields, etc, added to the header.
Loop updated to pay attention to GICR_TYPER.Last.
Derive frame "stride" size from GICR_TYPER.VLPIS.
Note: The assumption is that the redistributors are adjacent for
all CPUs. However this may not be the case for NUMA systems.