Increase max number of ports for stm32h7
which supports up to 8 uart and usart instances.
Signed-off-by: NGerald Baeza <gerald.baeza@st.com>
Signed-off-by: NBich Hemon <bich.hemon@st.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>