Update the various GIC ID and feature registers for GICv4:
 * PIDR2 [7:4] is the GIC architecture revision
 * GICD_TYPER.DVIS is 1 to indicate direct vLPI injection support
 * GICR_TYPER.VLPIS is 1 to indicate redistributor support for vLPIs
 * GITS_TYPER.VIRTUAL is 1 to indicate vLPI support
 * GITS_TYPER.VMOVP is 1 to indicate that our VMOVP implementation
   handles cross-ITS synchronization for the guest
 * ICH_VTR_EL2.nV4 is 0 to indicate direct vLPI injection support

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20220408141550.1271295-38-peter.maydell@linaro.org