boards: Add backward compatibility for renamed FVP boards

Add deprecated.cmake mappings to redirect old board names to new
unified structure:

- fvp_base_revc_2xaemv8a
→ fvp_base_revc_2xaem/v8a

- fvp_base_revc_2xaemv8a/fvp_base_revc_2xaemv8a/smp
→ fvp_base_revc_2xaem/v8a/smp

- fvp_base_revc_2xaemv8a/fvp_base_revc_2xaemv8a/smp/ns
→ fvp_base_revc_2xaem/v8a/smp/ns

This ensures existing build commands and documentation continue to work
with deprecation warnings while transitioning to the new board structure.

Signed-off-by: Nicolas Pitre <[email protected]>

Author: Nicolas Pitre

boards/deprecated.cmake

@@ -67,3 +67,12 @@ set(esp32_devkitc_wrover/esp32/appcpu_DEPRECATED
 set(scobc_module1_DEPRECATED
     scobc_a1
 )
+set(fvp_base_revc_2xaemv8a_DEPRECATED
+    fvp_base_revc_2xaem/v8a
+)
+set(fvp_base_revc_2xaemv8a/fvp_base_revc_2xaemv8a/smp_DEPRECATED
+    fvp_base_revc_2xaem/v8a/smp
+)
+set(fvp_base_revc_2xaemv8a/fvp_base_revc_2xaemv8a/smp/ns_DEPRECATED
+    fvp_base_revc_2xaem/v8a/smp/ns
+)