i2c: stm32f7: support DT binding i2c-analog-filter

Replace driver internally coded enabling/disabling of the
analog-filter with the DT binding "i2c-analog-filter".

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>