x86/paravirt: Clean up paravirt macros

Some paravirt macros are no longer used, delete them.

Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20200815100641.26362-3-jgross@suse.com