can: hi311x: hi3110_can_probe(): try to get crystal clock rate from property

can: hi311x: hi3110_can_probe(): try to get crystal clock rate from property

In some configurations, mainly ACPI-based, the clock frequency of the
device is supplied by very well established 'clock-frequency'
property. Hence, try to get it from the property at last if no other
providers are available.

Link: https://lore.kernel.org/all/20211206165542.69887-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>