i2c: designware: Remove useless driver specific option for I2C target

i2c: designware: Remove useless driver specific option for I2C target

The generic option for I2C target is already user selectable,
which makes the DesignWare specific option completely
unnecessary. The DesignWare option also silently selected
I2C_SLAVE instead of depending on it without any real need
for it.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20251218151509.361617-2-heikki.krogerus@linux.intel.com