Fix undefined reference in i2c_sibyte_exit().

   drivers/built-in.o: In function `i2c_sibyte_exit':
   i2c-sibyte.c:(.exit.text+0x368): undefined reference to `i2c_del_bus'
   i2c-sibyte.c:(.exit.text+0x368): relocation truncated to fit: R_MIPS_26 against `i2c_del_bus'
   i2c-sibyte.c:(.exit.text+0x38c): undefined reference to `i2c_del_bus'
   i2c-sibyte.c:(.exit.text+0x38c): relocation truncated to fit: R_MIPS_26 against `i2c_del_bus'
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>