common: add prototype & rename populate_serial_number()

Rename populate_serial_number() to a more descriptive
serial_read_from_eeprom() and provide the missing function prototype.

This is useful for boards that wish to read their serial number from
EEPROM at init.

Signed-off-by: Artur Rojek <artur@conclusive.pl>
Reviewed-by: Simon Glass <sjg@chromium.org>

cmd/tlv_eeprom.c

@@ -1088,19 +1088,7 @@ int mac_read_from_eeprom(void)
 	return 0;
 }
 
-/**
- *  populate_serial_number - read the serial number from EEPROM
- *
- *  This function reads the serial number from the EEPROM and sets the
- *  appropriate environment variable.
- *
- *  The environment variable is only set if it has not been set
- *  already.  This ensures that any user-saved variables are never
- *  overwritten.
- *
- *  This function must be called after relocation.
- */
-int populate_serial_number(int devnum)
+int serial_read_from_eeprom(int devnum)
 {
 	char serialstr[257];
 	int eeprom_index;

include/init.h

@@ -271,6 +271,20 @@ void board_init_r(struct global_data *id, ulong dest_addr)
 
 int cpu_init_r(void);
 int mac_read_from_eeprom(void);
+
+/**
+ *  serial_read_from_eeprom - read the serial number from EEPROM
+ *
+ *  This function reads the serial number from the EEPROM and sets the
+ *  appropriate environment variable.
+ *
+ *  The environment variable is only set if it has not been set
+ *  already. This ensures that any user-saved variables are never
+ *  overwritten.
+ *
+ *  This function must be called after relocation.
+ */
+int serial_read_from_eeprom(int devnum);
 int set_cpu_clk_info(void);
 int update_flash_size(int flash_size);
 int arch_early_init_r(void);