RISC-V: KVM: add support for SBI_FWFT_MISALIGNED_DELEG

RISC-V: KVM: add support for SBI_FWFT_MISALIGNED_DELEG

SBI_FWFT_MISALIGNED_DELEG needs hedeleg to be modified to delegate
misaligned load/store exceptions. Save and restore it during CPU
load/put.

Signed-off-by: Clément Léger <cleger@rivosinc.com>
Reviewed-by: Deepak Gupta <debug@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20250523101932.1594077-15-cleger@rivosinc.com
Signed-off-by: Anup Patel <anup@brainfault.org>