ARM: dove: add clock gating control

This patch adds clock gates from the clock gating control register
available on dove. All clock gates are hooked up to tclk, except for
gigabit ethernet controller (ge) which is a child of gephy to allow
both enabled/disabled at the same time.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>