i2c: use __weak

Cc: Heiko Schocher <hs@denx.de>
Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
diff --git a/drivers/i2c/i2c_core.c b/drivers/i2c/i2c_core.c
index 18d6736..d34b749 100644
--- a/drivers/i2c/i2c_core.c
+++ b/drivers/i2c/i2c_core.c
@@ -229,11 +229,9 @@
 }
 
 /* implement possible board specific board init */
-static void __def_i2c_init_board(void)
+__weak void i2c_init_board(void)
 {
 }
-void i2c_init_board(void)
-	__attribute__((weak, alias("__def_i2c_init_board")));
 
 /*
  * i2c_init_all():
@@ -395,9 +393,7 @@
 	i2c_write(addr, reg, 1, &val, 1);
 }
 
-void __i2c_init(int speed, int slaveaddr)
+__weak void i2c_init(int speed, int slaveaddr)
 {
 	i2c_init_bus(i2c_get_bus_num(), speed, slaveaddr);
 }
-void i2c_init(int speed, int slaveaddr)
-	__attribute__((weak, alias("__i2c_init")));