boards: shields: Add x_nucleo_idb05a1

Add shield x_nucleo_idb05a1.
Tested samples with the disco_l475_iot1 (SPI3 disabled to ensure
to test the shield on SPI1, and not the on-board BlueNRG-MS chip):
Beacon, Central and Peripheral have been tested and are working.

Signed-off-by: Yaël Boutreux <yael.boutreux@st.com>
Signed-off-by: Erwan Gouriou <erwang.gouriou@linaro.org>