Revert "arm: dcc_tty: fix armv6 dcc tty build failure"

This reverts commit 0274b1c9.

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: I8110a4fd649b8ac1ec9bfac00255c1214135e4b2
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>