i2c: mux: pca954x: support property idle-state

i2c: mux: pca954x: support property idle-state

This supports property idle-state,if present,
overrides i2c-mux-idle-disconnect.

My use cases:
	- Use the property idle-state to fix
	  an errata on LS2085ARDB and LS2088ARDB.
	- Errata id: E-00013(board LS2085ARDB and
	  LS2088ARDB revision on Rev.B, Rev.C and Rev.D).
	- About E-00013:
	  - Description: I2C1 and I2C3 buses
	    are missing pull-up.
	  - Impact: When the PCA954x device is tri-stated, the I2C bus
	    will float. This makes the I2C bus and its associated
	    downstream devices inaccessible.
	  - Hardware fix: Populate resistors R189 and R190 for I2C1
	    and resistors R228 and R229 for I2C3.
	  - Software fix: Remove the tri-state option from the PCA954x
	    driver(PCA954x always on enable status, specify a
	    channel zero in dts to fix the errata E-00013).

Tested-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: Biwen Li <biwen.li@nxp.com>
Signed-off-by: Peter Rosin <peda@axentia.se>