RISC-V: KVM: Use correct restricted types

__le32 and __le64 types should be used with le32_to_cpu() and
le64_to_cpu() and __user is needed for pointers referencing
guest memory, as sparse helpfully points out.

Fixes: e9f12b5f

 ("RISC-V: KVM: Implement SBI STA extension")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401020142.lwFEDK5v-lkp@intel.com/
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>