x86/PVH: adjust function/data placement

x86/PVH: adjust function/data placement

Two of the variables can live in .init.data, allowing the open-coded
placing in .data to go away. Another "variable" is used to communicate a
size value only to very early assembly code, which hence can be both
const and live in .init.*. Additionally two functions were lacking
__init annotations.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/3b0bb22e-43f4-e459-c5cb-169f996b5669@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>