tty: serial: samsung: Improve naming for common macro

tty: serial: samsung: Improve naming for common macro

Having "_USI" suffix in EXYNOS_COMMON_SERIAL_DRV_DATA_USI() macro is
confusing. Rename it to just EXYNOS_COMMON_SERIAL_DRV_DATA() and provide
USI registers availability for all Exynos variants instead. While at it,
also convert .has_usi field type to bool, so its usage is more obvious.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Link: https://lore.kernel.org/r/20211005095800.2165-1-semen.protsenko@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>