TTY: rocket, fix compilation warning

When CONFIG_PCI is unset, we see these warnings in rocket:
  drivers/tty/rocket.c:3140:13: warning: 'rmSpeakerReset' defined but not used
  drivers/tty/rocket.c:2599:12: warning: 'sPCIInitController' defined but not used

Fix those by moving the functions to one place and make them depend on
CONFIG_PCI.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Toralf Foerster <toralf.foerster@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>