[PATCH] sata_sil24: don't set probe_ent->mmio_base

sata_sil24 doesn't make use of probe_ent->mmio_base and setting this
field causes the area to be released twice on detach.  Don't set
probe_ent->mmio_base.

Signed-off-by: Tejun Heo <htejun@gmail.com>