KVM: riscv: selftests: Add Svade and Svadu Extension to get-reg-list test

Update the get-reg-list test to test the Svade and Svadu Extensions are
available for guest OS.

Signed-off-by: Yong-Xuan Wang <yongxuan.wang@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://lore.kernel.org/r/20240726084931.28924-6-yongxuan.wang@sifive.com


Signed-off-by: Anup Patel <anup@brainfault.org>