[PATCH] riscv: dts: sifive unmatched: Expose the FU740 core supply regulator.

[Vincent Pelletier <plr.vincent@gmail.com>]

Provides monitoring of core voltage and current:
tps544b20-i2c-0-1e
Adapter: i2c-ocores
vout1:       906.00 mV
temp1:        -40.0°C  (high = +125.0°C, crit = +150.0°C)
iout1:         5.06 A  (max = +20.00 A, crit max = +26.00 A)

Signed-off-by: Vincent Pelletier <plr.vincent@gmail.com>

--
Note for review: this patch has one warning from checkpatch.pl:
  WARNING: DT compatible string "tps544b20" appears un-documented -- check ./Documentation/devicetree/bindings/
  #32: FILE: arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts:55:
  +               compatible = "tps544b20";
This chip is handled by the existing pmbus module, and there is indeed no
matching entry in Documentation/devicetree/bindings/hwmon/pmbus. I am not
especially knowledgeable about this chip, I only know it is used by this
board, so I am not sure I can do the best job in putting such a file
together.
If needed I can git it a try.
---
 arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts b/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
index 270360b258b7..e327831d0d48 100644
--- a/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
+++ b/arch/riscv/boot/dts/sifive/hifive-unmatched-a00.dts
@@ -51,6 +51,11 @@ &uart1 {
 &i2c0 {
 	status = "okay";
 
+	tps544b20@1e {
+		compatible = "tps544b20";
+		reg = <0x1e>;
+	};
+
 	temperature-sensor@4c {
 		compatible = "ti,tmp451";
 		reg = <0x4c>;
-- 
2.33.1