Fix linker scripts

Remove PROVIDE_HIDDEN and ONLY_IF_{RO,RW} from linker scripts to make
them work with older binutils versions.  Fixes *-bsd-user build on
OpenBSD 4.9 which ships binutils 2.15.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>