dt-bindings: input: iqs7222: Correct minimum slider size

The minimum slider size enforced by the driver is 1 or 16 for the
IQS7222C or IQS7222A, respectively.

Fixes: 44dc42d2 ("dt-bindings: input: Add bindings for Azoteq IQS7222A/B/C")
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/Y1SRU37t74wRvZv3@nixie71


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>