clk: u300: Terminate of match table

Failure to terminate this match table can lead to boot failures
depending on where the compiler places the match table.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mike Turquette <mturquette@linaro.org>