parisc: Clean up linker script using new linker script macros.

This patch has the (likely harmless) side effect of moving
.data.init_task inside the _edata.

It also changes the alignment of .data.init_task from 16384 to
THREAD_SIZE, which can in some configurations be larger than 16384.  I
believe that this change fixes a potential bug on those
configurations.

Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-parisc@vger.kernel.org
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>