clk: versatile: off by one in clk_sp810_timerclken_of_get()

The ">" should be ">=" or we end up reading beyond the end of the array.

Fixes: 6e973d2c

 ('clk: vexpress: Add separate SP810 driver')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>