[PATCH] shpchp: cleanup bus speed handling

The code related to handling bus speed in SHPCHP driver is
unnecessarily complex. This patch cleans up and simplify that.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>