arm64: dts: ti: iot2050: Flip mmc device ordering on Advanced devices

This ensures that the SD card will remain mmc0 across Basic and Advanced
devices, also avoiding surprises for users coming from the downstream
kernels.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Acked-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/fe20d6346f119a28e47d129b616682001299cf0e.1632657917.git.jan.kiszka@web.de