ASoC: nau8824: change FVCO maximum threshold

Change the maximum of FDCO which remains between 90MHz-100MHz.
FDCO must be within the 90MHz-100MHz or the FFL cannot be
guaranteed across the full range of operation.

Signed-off-by: John Hsu <KCHSU0@nuvoton.com>
Signed-off-by: Mark Brown <broonie@kernel.org>