KVM: arm64: nv: Add new HDFG[R|W]TR2_GROUP for corresponding FGU handling

This adds new HDFG[R|W]TR2_GROUP in enum fgt_group_id for corresponding FGU
handling related to HDFGRTR2_EL2 and HDFGWTR2_EL2 registers.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>