tty: serial: samsung_tty: build it for any platform

tty: serial: samsung_tty: build it for any platform

There is no need to tie this driver to only a specific SoC, or compile
test, so remove that dependancy from the Kconfig rules.

Cc: linux-kernel@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Shinbeom Choi <sbeom.choi@samsung.com>
Cc: HYUN-KI KOO <hyunki00.koo@samsung.com>
Cc: Hyunki Koo <kkoos00@naver.com>
Cc: Donghoon Yu <hoony.yu@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200220102628.3371996-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>