boards: Set full_name for all boards

Full name was set based on the information available either in board
documentation or in Twister files.
Whenever applicable, vendor name was dropped from the full name so that
all boards have a consistent naming scheme.

Signed-off-by: Benjamin Cabé <benjamin@zephyrproject.org>
diff --git a/boards/brcm/bcm958402m2/board.yml b/boards/brcm/bcm958402m2/board.yml
index e9ad177..85a0692 100644
--- a/boards/brcm/bcm958402m2/board.yml
+++ b/boards/brcm/bcm958402m2/board.yml
@@ -1,5 +1,6 @@
 board:
   name: bcm958402m2
+  full_name: BCM958402M2 (Cortex-M7)
   vendor: brcm
   socs:
   - name: bcm58402