siimage: remove proc_reports_siimage()

* proc_reports_siimage() is now only called by init_chipset_siimage()
  so inline it there.

* Use array instead of switch statement for reporting clock modes.

There should be no functional changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>