arm: stm32mp: support 2 MAC address for STM32MP13

Add support of several MAC address in OTP (3 32bits OTP word for
2 MAC address) for SOCs in  STM32MP13x family: STM32MP133 and STM32MP135.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
diff --git a/arch/arm/mach-stm32mp/include/mach/sys_proto.h b/arch/arm/mach-stm32mp/include/mach/sys_proto.h
index 829b3fe..4b564e8 100644
--- a/arch/arm/mach-stm32mp/include/mach/sys_proto.h
+++ b/arch/arm/mach-stm32mp/include/mach/sys_proto.h
@@ -64,6 +64,7 @@
 /* return boot mode */
 u32 get_bootmode(void);
 
+int get_eth_nb(void);
 int setup_mac_address(void);
 
 /* board power management : configure vddcore according OPP */