The RTC's main clock, used internally and exported to the rest of the
SoC, is called "LOSC" (low speed oscillator) through the hardware
documentation.

This patch adds a default name for this clock, in case the device tree
does not provide one. This shouldn't happen, but lets play it safe.
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Tested-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>