programs: cmake: Use list of executables

Use list of executables to:
- factorize the code to define executables
- highlight the similarities and differences of the executable definitions
- avoid list duplication

Use alphabetic order for executables in lists.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>

programs/util/CMakeLists.txt

@@ -2,12 +2,16 @@ set(libs
     mbedcrypto
 )
 
-add_executable(strerror strerror.c)
-target_link_libraries(strerror ${libs})
+set(executables
+    pem2der
+    strerror
+)
 
-add_executable(pem2der pem2der.c)
-target_link_libraries(pem2der ${libs})
+foreach(exe IN LISTS executables)
+    add_executable(${exe} ${exe}.c)
+    target_link_libraries(${exe} ${libs})
+endforeach()
 
-install(TARGETS strerror pem2der
+install(TARGETS ${executables}
         DESTINATION "bin"
         PERMISSIONS OWNER_READ OWNER_WRITE OWNER_EXECUTE GROUP_READ GROUP_EXECUTE WORLD_READ WORLD_EXECUTE)