parisc: Allow building 64-bit kernel without -mlong-calls compiler option

A 64-bit kernel built without CONFIG_MLONGCALLS (-mlong-calls compiler
option) usually fails to link because of unreachable functions.  Try to
work around that linking issue by moving the *.init and *.exit text
segments closer to the main text segment. With that change those
segments now don't get freed at runtime any longer, but since we in most
cases run with huge-page enabled, we ignore the lost memory in
preference of better performance.

This change will not guarantee that every kernel config will now
sucessfully build with short calls and without linking issues.

Signed-off-by: Helge Deller <deller@gmx.de>