The SD card on the SoPine SoM module is somewhat concealed, so was
originally defined as "non-removable".
However there is a working card-detect pin (tested on two different
SoM versions), and in certain SoM base boards it might be actually
accessible at runtime.
Also the Pine64-LTS shares the SoPine base .dtsi, so inherited the
non-removable flag, even though the SD card slot is perfectly accessible
and usable there. (It turns out that just *my* board has a broken card
detect switch, so I originally thought CD wouldn't work on the LTS.)

Drop the "non-removable" flag to describe the SD card slot properly.

Fixes: c3904a26 ("arm64: allwinner: a64: add DTSI file for SoPine SoM")
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20210113152630.28810-5-andre.przywara@arm.com