Add DCC earlycon support for early printks. The patch is useful for SoC
bringup where HW serial console is broken.
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/41e2920a6348e65b2e986b0e65b66531e87cd756.1570543923.git.michal.simek@xilinx.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>