dt-bindings: clk: rs9: Fix DIF pattern match

dt-bindings: clk: rs9: Fix DIF pattern match

The pattern match [0-19] is incorrect and does not cover range of 0..19,
use pattern 1?[0-9] to cover range 0..19 instead. Update the example to
validate all parts of the pattern match and prevent such failures in the
future.

Fixes: 26c1bc67aa2f ("dt-bindings: clk: rs9: Add Renesas 9-series I2C PCIe clock generator")
Signed-off-by: Marek Vasut <marek.vasut@mailbox.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>