hw/intc/arm_gicv3_kvm: Implement get/put functions

This actually implements pre_save and post_load methods for in-kernel
vGICv3.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>
Message-id: 1487850673-26455-4-git-send-email-vijay.kilari@gmail.com
[PMM:
 * use decimal, not 0bnnn
 * fixed typo in names of ICC_APR0R_EL1 and ICC_AP1R_EL1
 * completely rearranged the get and put functions to read and write
   the state in a natural order, rather than mixing distributor and
   redistributor state together]
Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com>
[Vijay:
 * Update macro KVM_VGIC_ATTR
 * Use 32 bit access for gicd and gicr
 * GICD_IROUTER, GICD_TYPER, GICR_PROPBASER and GICR_PENDBASER reg
   access  are changed from 64-bit to 32-bit access
 * Add ICC_SRE_EL1 save and restore
 * Dropped translate_fn mechanism and coded functions to handle
   save and restore of edge_trigger and priority
 * Number of APnR register saved/restored based on number of
   priority bits supported]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>