serial: samsung: Enable baud clock for UART reset procedure in resume

Ensure that the baud clock is also enabled for UART register writes in
driver resume. On Exynos5433 SoC this is needed to avoid external abort
issue.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>