In sandybridge_pcode_read and sandybridge_pcode_write,
extend the mbox parameter from u8 to u32.
On Haswell and Sandybridge, bits 7:0 encode the mailbox
command and bits 28:8 are used for address control for
specific commands.
Based on suggestion from Ville Syrjälä.
Signed-off-by: Tom O'Rourke <Tom.O'Rourke@intel.com> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>