Tacoma: add OBMC_POWER_SUPPLY_INSTANCES

Tacoma was missing the OBMC_POWER_SUPPLY_INSTANCES config, and thus the
power supply monitor service will not start correctly.

And with the change in
https://gerrit.openbmc-project.xyz/c/openbmc/meta-phosphor/+/27463
the build will fail on constructing the rootfs.

Fix it by adding OBMC_POWER_SUPPLY_INSTANCES in tacoma config.

(From meta-ibm rev: 1f2b96d73f0117b9c07ce7e4beca0e1dfddfb8e2)

Change-Id: I20f1ca81642bb1d594aa783ca3872b6bd08720da
Signed-off-by: Lei YU <mine260309@gmail.com>
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-ibm/meta-witherspoon/conf/machine/witherspoon-tacoma.conf b/meta-ibm/meta-witherspoon/conf/machine/witherspoon-tacoma.conf
index e8a3830..2184847 100644
--- a/meta-ibm/meta-witherspoon/conf/machine/witherspoon-tacoma.conf
+++ b/meta-ibm/meta-witherspoon/conf/machine/witherspoon-tacoma.conf
@@ -1,6 +1,8 @@
 KERNEL_DEVICETREE = "aspeed-bmc-opp-tacoma.dtb"
 UBOOT_MACHINE = "evb-ast2600_defconfig"
 
+OBMC_POWER_SUPPLY_INSTANCES = "0 1"
+
 MACHINEOVERRIDES =. "ibm-ac-server:witherspoon:"
 require conf/machine/include/ast2600.inc
 require conf/machine/include/obmc-bsp-common.inc