i2c: mux: pca954x: add support for NXP PCA984x family

This patch extends the current i2c-mux-pca954x driver and adds support for
a newer PCA984x family of the I2C switches and multiplexers from NXP.

Signed-off-by: Adrian Fiergolski <adrian.fiergolski@cern.ch>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Peter Rosin <peda@axentia.se>