Revert "[ARM] armv6 dcc tty driver"

This reverts commit 0ddfd45d.

Drop AOSP's "armv6 dcc tty driver" in favor of upstream DCC driver for
ARMv6/v7 16c63f8e (drivers: char: hvc: add arm JTAG DCC console support).

Change-Id: I0ca651ef2d854fff03cee070524fe1e3971b6d8f
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>