dt-bindings: Add binding for IDT 8T49N24x UFT

dt-bindings: Add binding for IDT 8T49N24x UFT

IDT8T49N241 has 4 outputs; 1 integral divider and 3 fractional dividers.
The 8T49N241 accepts up to two differential or single-ended input clocks
and a fundamental-mode crystal input. The internal PLL can lock to either
of the input reference clocks or just to the crystal to behave as a
frequency synthesizer.

Signed-off-by: David Cater <david.cater@idt.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>