ARM: stm32: Allow overriding setup_mac_address()

Let board code override setup_mac_address(), which is useful e.g. if the
board derives the MAC address from another source, like an I2C EEPROM.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/arch/arm/mach-stm32mp/cpu.c b/arch/arm/mach-stm32mp/cpu.c
index 6a71465..de7891b 100644
--- a/arch/arm/mach-stm32mp/cpu.c
+++ b/arch/arm/mach-stm32mp/cpu.c
@@ -456,7 +456,7 @@
  * If there is no MAC address in the environment, then it will be initialized
  * (silently) from the value in the OTP.
  */
-static int setup_mac_address(void)
+__weak int setup_mac_address(void)
 {
 #if defined(CONFIG_NET)
 	int ret;