arm64: dts: allwinner: a527: cubie-a5e: Drop external 32.768 KHz crystal

arm64: dts: allwinner: a527: cubie-a5e: Drop external 32.768 KHz crystal

The Radxa Cubie A5E has empty pads for a 32.768 KHz crystal, but it is
left unpopulated, as per the schematics and seen on board images. A dead
give away is the RTC's LOSC auto switch register showing the external
OSC to be abnormal.

Drop the external crystal from the device tree. It was not referenced
anyway.

Fixes: c2520cd032ae ("arm64: dts: allwinner: a523: add Radxa A5E support")
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patch.msgid.link/20250913102450.3935943-1-wens@kernel.org
Signed-off-by: Chen-Yu Tsai <wens@csie.org>