Add support for power supplies

Requires updating the kernel with a driver for the power supplies. The
current linux tree can be found in cesnet/2021-05-14.

Depends-on: https://cesnet-gerrit-czechlight/c/CzechLight/velia/+/4188
Depends-on: https://gerrit.cesnet.cz/c/CzechLight/velia/+/4188
Change-Id: I57f426feaf48a72b5b95c961e45f90323777d685
diff --git a/board/czechlight/clearfog/linux.fragment b/board/czechlight/clearfog/linux.fragment
index 825b98b..d939b71 100644
--- a/board/czechlight/clearfog/linux.fragment
+++ b/board/czechlight/clearfog/linux.fragment
@@ -11,6 +11,7 @@
 # PMBus for the PSUs
 CONFIG_PMBUS=y
 CONFIG_SENSORS_PMBUS=y
+CONFIG_SENSORS_FSP_3Y=y
 
 # SPI-to-Quad-UART
 CONFIG_SERIAL_MAX310X=y