The eMMC and SD card on the sc598 share pins, so they cannot be
used at the same time. Previously, this was managed with a patch applied
by the relevant build system, but patches are brittle and have to be
maintained. Instead, they have been replaced with two separate device trees
, one for eMMC and one for SD card, which inherit a shared base dtsi.
The build system can then select between the default device tree which
enabled eMMC or the other device tree which enables SD card support.
Signed-off-by: Caleb Ethridge <caleb.ethridge@analog.com>