rtc: imxdi: Soften dependencies for improved compile coverage

The driver compiles fine on x86_64, so soften the dependencies to
ARCH_MXC || COMPILE_TEST.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231002080529.2535610-2-u.kleine-koenig@pengutronix.de


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>