board: stm32mp1: use IS_ENABLED to prevent ifdef in board_check_usb_power

Use IS_ENABLED to prevent ifdef in board_check_usb_power.

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