cppcheck: Provide consistent reason formatting for all cppcheck-suppresses

cpu/arm7_common/bootloader.c

cpu/x86/x86_pci.c

sys/include/timex.h

sys/net/gnrc/network_layer/ndp/internal/gnrc_ndp_internal.c

sys/net/gnrc/network_layer/sixlowpan/frag/rbuf.c

sys/net/gnrc/routing/rpl/gnrc_rpl_control_messages.c

sys/net/gnrc/sock/ip/gnrc_sock_ip.c

sys/net/gnrc/sock/udp/gnrc_sock_udp.c

sys/posix/sockets/posix_sockets.c

tests/cpp11_condition_variable/main.cpp

tests/unittests/tests-base64/tests-base64.c

tests/unittests/tests-cbor/tests-cbor.c

tests/unittests/tests-fib/tests-fib.c