tests: code_relocation: use per-SoC linker file for Arm tests

In order to support more Arm SoCs, extend the SoC-specific linker file
instead of the default arch linker file.

Fixes #60165

Signed-off-by: Manuel Argüelles <manuel.arguelles@nxp.com>

tests/application_development/code_relocation/linker_arm_sram2.ld

@@ -36,4 +36,5 @@ MEMORY
 #endif
     }
 
-#include <zephyr/arch/arm/aarch32/cortex_m/scripts/linker.ld>
+/* Include the SoC-specific linker file */
+#include <linker.ld>