clk: at91: fix num_parents test in at91sam9260 slow clk implementation
clk: at91: fix num_parents test in at91sam9260 slow clk implementation

The slow clk block provided by at91sam9260 and derived SoCs should always
have 2 parents.

Signed-off-by: Boris BREZILLON <4e91513d4f418754031d3d36b3fc73980c40a38c@free-electrons.com>
Signed-off-by: Mike Turquette <6dab61939fc5e23761050a66932f032dceda5ebf@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs