target/riscv: Dump Hypervisor registers if enabled

target/riscv: Dump Hypervisor registers if enabled

Dump the Hypervisor registers and the current Hypervisor state.

While we are editing this code let's also dump stvec and scause.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>