serial: stm32x7: remove useless CONFIG_CLK and OF_CONTROL flag

This driver is currently used by STM32F7 and STM32H7 SoCs.
As CONFIG_CLK and OF_CONTROL flags are set by default for these
2 SoCs, this flag becomes useless in this driver, so remove it.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
1 file changed