s390/chsc: fix packed-not-aligned warnings

Remove attribute packed where possible failing this add proper alignment
information to fix warnings like the one below:

drivers/s390/cio/chsc.c: In function 'chsc_siosl':
drivers/s390/cio/chsc.c:1287:2: warning: alignment 1 of 'struct <anonymous>' is less than 4 [-Wpacked-not-aligned]
  } __attribute__ ((packed)) *siosl_area;

Note: this patch should be a nop since non of these structs use auto
storage but allocated pages. However there are changes to the generated
code because of additional padding at the end of some of the structs due
to alignment when memset(foo, 0, sizeof(*foo)) is used.

Signed-off-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>