Patch from Lennert Buytenhek

Add an initial implementation of the clk_* API for the cirrus ep93xx
to the tree.  The initial implementation is somewhat minimal, with the
intention of extending it as we go along.
Signed-off-by: NLennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>