ARM: dts: bcm283x: Fix console path on RPi3

ARM: dts: bcm283x: Fix console path on RPi3

Contrary to other RPi devices, RPi3 uses uart0 to communicate with
the BCM43438 bluetooth controller. uart1 is then used for the console.
Today, the console configuration is inherited from the bcm283x dtsi
(bootargs) which is not the correct one for the RPi3. This leads to
routing issue and confuses the Bluetooth controller with unexpected
data.

This patch introduces chosen/stdout path to configure console to uart0
on bcm283x family and overwrite it to uart1 in the RPi3 dts.

Create serial0/1 aliases referring to uart0 and uart1 paths.
Remove unneeded earlyprintk.

Fixes: 4188ea2aeb6d ("ARM: bcm283x: Define UART pinmuxing on board level")
Signed-off-by: Loic Poulain <loic.poulain@gmail.com>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>