i2c: fti2c010: remove unused/unmaintained driver

CONFIG_SYS_I2C_FTI2C010 is not enabled by anyone.

Commit 28527096 ("dm: i2c: Add a note to I2C drivers which need
conversion") prompted to convert this driver to DM before June 2017,
but not converted yet.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Heiko Schocher <hs@denx.de>