schemas: legacy: add tps25990 PSUSensor

Added for TPS25990 support in dbus-sensors patch [1].

[1] https://gerrit.openbmc.org/c/openbmc/dbus-sensors/+/81862

Change-Id: I108c700da828bacfa969aeed4f6518f1ae67f8f6
Signed-off-by: Kevin Tung <kevin.wtmh@gmail.com>
diff --git a/schemas/legacy.json b/schemas/legacy.json
index e548228..75a2500 100644
--- a/schemas/legacy.json
+++ b/schemas/legacy.json
@@ -969,6 +969,7 @@
                         "smpro_hwmon",
                         "SY24655",
                         "TDA38640",
+                        "TPS25990",
                         "TPS53679",
                         "TPS546D24",
                         "XDP710",