target/riscv: add shtvala

target/riscv: add shtvala

shtvala is described in RVA22 as:

"htval must be written with the faulting guest physical address
in all circumstances permitted by the ISA."

This is the case since commit 3067553993, so claim support for shtvala.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241218114026.1652352-6-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>