clocksource/drivers/davinci: Move pr_fmt() before the includes

We no longer need to undef pr_fmt if we define our own before including
any headers.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: David Lechner <david@lechnology.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210111140814.3668-1-brgl@bgdev.pl