mfd: max77686: do not set i2c client data for rtc i2c client

mfd: max77686: do not set i2c client data for rtc i2c client

There is different RTC I2C address for RTC block in MAX77686.
Driver is creating dummy i2c client for this address to access
the register of this IP block.

As there is no call to i2c_get_clientdata() for rtc_i2c client,
there is no need to store pointer and hence removing the call
to set client data for rtc i2c client.

Suggested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>