UPSTREAM: tty: serial: samsung_tty: do not abuse the struct uart_port unused fields

The samsung_tty driver was trying to abuse the struct uart_port by using
two "empty" bytes for its own use.  That's not ok, and was found by
removing those fields from the structure.

Move the variables into the port-specific structure, which is where
everything else for this port already is.  There is no space wasted here
as there was an empty "hole" in the structure already for these bytes.

Bug: 144661360
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Hyunki Koo <kkoos00@naver.com>
Cc: HYUN-KI KOO <hyunki00.koo@samsung.com>
Cc: Shinbeom Choi <sbeom.choi@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Dmitry Safonov <dima@arista.com>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/20191217140232.GA3489190@kroah.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 8336240ebb248b46c778f28123a7ceec9817c3d2)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I5c1c7ae6e2344239da3eb0815e1f0efbe629d58c