staging: nvec: fix clock setup

commit 30b68231 "ARM: tegra: clock: add i2c fast clock entry in clock table"
added a new clock for the i2c controllers, so clock requests are no longer
conclusive. Fix this by specifying "div-clk" explicitly.

Signed-off-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>