clk: clk-vf610: Add clock for Vybrid OCOTP controller

Add clock support for Vybrid On-Chip One Time Programmable
(OCOTP) controller.

While the OCOTP block does not require explicit clock gating,
for programming the OCOTP timing register the clock rate of
ipg clock is required for timing calculations related to fuse
and shadow register read sequence. We explicitly specify the
ipg clock for OCOTP as a result.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>