board: stm32mp1: use IS_ENABLED to prevent ifdef in set_dfu_alt_inf

Use CONFIG_IS_ENABLED to prevent ifdef in set_dfu_alt_inf.

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