pv_console: remove unnecessary #ifdefs

pv_console: remove unnecessary #ifdefs

The header for PV console contains empty function definitions in case of
!CONFIG_XEN_GUEST specially to avoid #ifdefs in a code that uses them
to make the code look cleaner.

Unfortunately, during the release of shim-comet, PV console functions
were enclosed into unnecessary #ifdefs CONFIG_X86. Remove them.

Signed-off-by: Sergey Dyasli <sergey.dyasli@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>