KVM: arm64: nv: Add FEAT_FGT2 registers based FGU handling

This enables FEAT_FGT2 registers based FGU handling by adding the following
new groups in 'enum fgt_group_id' for all respective FGT control registers
and also adding FGU behaviour for their individual managed registers access
traps.

1. HDFGRTR2_GROUP
2. HDFGWTR2_GROUP
3. HFGRTR2_GROUP
4. HFGWTR2_GROUP
5. HFGITR2_GROUP

Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: kvmarm@lists.linux.dev
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>