i2c: qcom-geni: Grow a dev pointer to simplify code

Some lines are long here. Use a struct dev pointer to shorten lines and
simplify code. The clk_get() call can fail because of EPROBE_DEFER
problems too, so just remove the error print message because it isn't
useful. Finally, platform_get_irq() already prints an error so just
remove that error message.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>