riscv: Add vector crypto extensions support

When the vector extensions are available expose them to the guest
via device tree so that guest can use it. This includes extensions
Zvbb, Zvbc, Zvkb, Zvkg, Zvkned, Zvknha, Zvknhb, Zvksed, Zvksh,
and Zvkt.

Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240325153141.6816-6-apatel@ventanamicro.com


Signed-off-by: Will Deacon <will@kernel.org>