I have tried again with one of the latest f28 build (20180419), same
Tried it myself.
I was able do build bcm2837-rpi-3-b.dtb file applying the patch written in some previous
message in this thread.
Even if /dev/spidev0.0 and /dev/spidev0.1 are in place, and fdtget
/boot/dtb/bcm2837-rpi-3-b.dtb /soc/spi@7e204000 status is okay, spidev and spi_bcm2835 are
loaded, I have such errors in the dmesg  starting with "spidev spi0.0: buggy DT:
spidev listed directly in DT".
Then, as usual without understanding very well what I'm doing :-) using some tools to
test SPI (spincl, airspayce library, wiringpi, Adafruit_Nokia_LCD) I get segmentation
faults or messages like "mmap (GPIO) failed: Operation not permitted".