ASoC: wm8960: Fix PLL register writes

commit 85fa532b6ef920b32598df86b194571a7059a77c upstream.

Bit 9 of PLL2,3 and 4 is reserved as '0'. The 24bit fractional part
should be split across each register in 8bit chunks.

Signed-off-by: Mike Dyer <mike.dyer@md-soft.co.uk>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>