armv8: aarch64: Fix the warning about x1-x3 nonzero issue

armv8: aarch64: Fix the warning about x1-x3 nonzero issue

For 64-bit kernel, there is a warning about x1-x3 nonzero in violation
of boot protocol. To fix this issue, input argument 4 is added for
armv8_switch_to_el2 and armv8_switch_to_el1. The input argument 4 will
be set to the right value, such as zero.

Signed-off-by: Alison Wang <[email protected]>
Reviewed-by: Alexander Graf <[email protected]>
Tested-by: Ryan Harkin <[email protected]>
Tested-by: Michal Simek <[email protected]>
Reviewed-by: York Sun <[email protected]>