parisc: Fix kernel memory layout regarding position of __gp

Architecturally we need to keep __gp below 0x1000000.

But because of ftrace and tracepoint support, the RO_DATA_SECTION now gets much
bigger than it was before. By moving the linkage tables before RO_DATA_SECTION
we can avoid that __gp gets positioned at a too high address.

Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Helge Deller <deller@gmx.de>