[S390] clean up linker script using new linker script macros.

Note that this patch moves .data.init_task inside _edata.  In
addition, the alignment of .init.ramfs changes: It is now PAGE_ALIGNED
and __initramfs_end is arbitrarily aligned; Previously it was
only aligned to a 0x100-byte boundary, and always ended on an even
byte.

This change results in fewer output sections and in some data being
reordered, but should have no functional effect.

Signed-off-by: Nelson Elhage <nelhage@ksplice.com>
Signed-off-by: Tim Abbott <tabbott@ksplice.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-s390@vger.kernel.org
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>