nvmem: imx-ocotp: Add i.MX7D timing write clock setup support

This patch adds logic to correctly setup the write timing parameters
when blowing an OTP fuse for the i.MX7S/D.

Fixes: 0642bac7 ("nvmem: imx-ocotp: add write support")

Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>