llext-edk: fix BOARD_TARGET variable generation to be Zephyr-compatible

The board revision is not part of the NORMALIZED_BOARD_TARGET variable
as composed by Zephyr, so it must also not be used in the EDK exported
value to avoid mismatches. The revision is exported as a separate
variable, so it can still be used to differentiate between board
revisions.

Signed-off-by: Luca Burelli <l.burelli@arduino.cc>

cmake/llext-edk.cmake

@@ -166,8 +166,7 @@ yaml_get(board_qualifiers NAME build_info KEY cmake board qualifiers)
 yaml_get(board_revision NAME build_info KEY cmake board revision)
 zephyr_build_string(normalized_board_target
     BOARD ${board_name}
-    BOARD_QUALIFIERS ${board_qualifiers}
+    BOARD_QUALIFIERS ${board_qualifiers})
-    BOARD_REVISION ${board_revision})
 
 set(llext_edk_name ${CONFIG_LLEXT_EDK_NAME})
 set(llext_edk ${PROJECT_BINARY_DIR}/${llext_edk_name})