dt-bindings: ti-serdes-mux: Add defines for AM64 SoC

AM64 has a single lane SERDES which can be configured to be used
with either PCIe or USB. Define the possilbe values for the SERDES
function in AM64 SoC here.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Link: https://lore.kernel.org/r/20210721155849.20994-7-kishon@ti.com

include/dt-bindings/mux/ti-serdes.h

@@ -90,4 +90,9 @@
 #define J7200_SERDES0_LANE3_USB			0x2
 #define J7200_SERDES0_LANE3_IP4_UNUSED		0x3
 
+/* AM64 */
+
+#define AM64_SERDES0_LANE0_PCIE0		0x0
+#define AM64_SERDES0_LANE0_USB			0x1
+
 #endif /* _DT_BINDINGS_MUX_TI_SERDES */