mux: Add support for reading mux state from consumer DT node

mux: Add support for reading mux state from consumer DT node

In some cases, we might need to provide the state of the mux to be set for
the operation of a given peripheral. Therefore, pass this information using
mux-states property.

Link: https://lore.kernel.org/lkml/20211123081222.27979-1-a-govindraju@ti.com
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Peter Rosin <peda@axentia.se> (minor edits)
Link: https://lore.kernel.org/r/aac25be8-9515-a980-f7cb-709938c84822@axentia.se
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>