dt-bindings: hwmon: ltc2978: add support for ltm4673

Add LTM4673 to supported devices of LTC2978. Unlike other LTM46xx
devices, LTM4673 is a μModule regulator that outputs to four channels.

Signed-off-by: Cedric Encarnacion <[email protected]>

Author: cencarna

Documentation/devicetree/bindings/hwmon/ltc2978.txt

@@ -20,6 +20,7 @@ Required properties:
   * "lltc,ltc7880"
   * "lltc,ltm2987"
   * "lltc,ltm4664"
+  * "lltc,ltm4673"
   * "lltc,ltm4675"
   * "lltc,ltm4676"
   * "lltc,ltm4677"
@@ -45,6 +46,7 @@ Valid names of regulators depend on number of supplies supported per device:
   * ltc3883 : vout0
   * ltc7841 : vout0
   * ltm4664 : vout0 - vout1
+  * ltm4673 : vout0 - vout3
   * ltm4675, ltm4676, ltm4677, ltm4678 : vout0 - vout1
   * ltm4680, ltm4686 : vout0 - vout1
   * ltm4700 : vout0 - vout1