ARM: meson: add unique MAC address generation

Add support for generating an unique MAC address using the SoC internal
serial number from the Secure Monitor interface.

The algorithm generates an unicast locally administered 6bytes minus 2bits
address using an crc16 of the serial for the top 16bits with the lower 2 bits
masked to setup the unicast locally administered property and a crc24 for
the lower 24bits.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

arch/arm/include/asm/arch-meson/eth.h

@@ -19,4 +19,7 @@ enum {
  */
 void meson_eth_init(phy_interface_t mode, unsigned int flags);
 
+/* Generate an unique MAC address based on the HW serial */
+int meson_generate_serial_ethaddr(void);
+
 #endif /* __MESON_ETH_H__ */

arch/arm/include/asm/arch-meson/sm.h

@@ -7,6 +7,9 @@
 #define __MESON_SM_H__
 
 ssize_t meson_sm_read_efuse(uintptr_t offset, void *buffer, size_t size);
+
+#define SM_SERIAL_SIZE	12
+
 int meson_sm_get_serial(void *buffer, size_t size);
 
 #endif /* __MESON_SM_H__ */