Tab5 ST7121 variant + fixes (#605)

Added the newest variant to the tab5, St7121.
Fixed variant detection reliability
Fixed tab5 camera WHO_AM_I failing sometimes
Fixed tab5 keyboard live rotation on boot and after stopping/starting lvgl

Drivers/st7121-module/include/bindings/st7121.h

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Apache-2.0
+#pragma once
+
+#include <tactility/bindings/bindings.h>
+#include <drivers/st7121.h>
+
+// The devicetree compiler derives the expected config typedef name from the compatible
+// string's suffix (e.g. "sitronix,st7121" -> st7121_config_dt), not from the node name or
+// driver name, so the tag here must match that exactly.
+DEFINE_DEVICETREE(st7121, struct St7121Config)