bcm2837-rpi-3-b.dts, its only in-tree user, was overriding it as
"brcm,bcm2837" already.
Fixes: 9d56c22a7861 ("ARM: bcm2835: Add devicetree for the Raspberry Pi 3.") Cc: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Andreas Färber <afaerber@suse.de> Signed-off-by: Eric Anholt <eric@anholt.net>