sh: crash kernel resource fix

The reserved crash kernel memory range is currently missing from
/proc/iomem. crashk_res is mistakenly setup after __add_active_range().
Reorder things to make sure the resource shows up in /proc/iomem.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>