i2c: Fix the comment to match the function described

Use the correct function name in the function description.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Heiko Schocher <hs@denx.de>

include/i2c.h

@@ -499,7 +499,8 @@ int i2c_get_chip(struct udevice *bus, uint chip_addr, uint offset_len,
 		 struct udevice **devp);
 
 /**
- * i2c_get_chip() - get a device to use to access a chip on a bus number
+ * i2c_get_chip_for_busnum() - get a device to use to access a chip on
+ *			       a bus number
  *
  * This returns the device for the given chip address on a particular bus
  * number.