gcc: Enable address-of-packed-member warnings

After having resolved all of the instances of packed member access,
re-enable the warning.

Fixes #16587.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

Author: carlescufi

cmake/compiler/gcc/compiler_flags.cmake

@@ -42,14 +42,6 @@ check_set_compiler_property(APPEND PROPERTY warning_base -Wpointer-arith)
 # not portable
 check_set_compiler_property(APPEND PROPERTY warning_base -Wexpansion-to-defined)
 
-if(CMAKE_CXX_COMPILER_VERSION VERSION_GREATER "9.1.0")
-  set_compiler_property(APPEND PROPERTY warning_base
-                        # FIXME: Remove once #16587 is fixed
-                        -Wno-address-of-packed-member
-  )
-endif()
-
-
 # GCC options for warning levels 1, 2, 3, when using `-DW=[1|2|3]`
 set_compiler_property(PROPERTY warning_dw_1
                       -Waggregate-return