mfd/extcon: max77693: Rename defines to allow inclusion with max77843

Add MAX77693 prefix to some of the defines used in max77693 extcon
driver so the max77693-private.h can be included simultaneously with
max77843-private.h.

Additionally use BIT() macro in header.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>