target/riscv: add shgatpa

target/riscv: add shgatpa

shgatpa is defined in RVA22 as:

"For each supported virtual memory scheme SvNN supported in satp, the
corresponding hgatp SvNNx4 mode must be supported. The hgatp mode Bare
must also be supported."

Claim support for shgatpa since this is always true for TCG.

Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241218114026.1652352-9-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>