Defines starting with `d' in osfmk/ppc/POWERMAC

• DCD_TIMEOUT osfmk/ppc/POWERMAC/scc_8530.h:417
• DEBUG_SCC osfmk/ppc/POWERMAC/serial_io.c:159
• DECL_FUNNEL_VARS osfmk/ppc/POWERMAC/serial_io.h:133
• DEFAULT_FLAGS osfmk/ppc/POWERMAC/serial_io.c:146
• DEFAULT_SPEED osfmk/ppc/POWERMAC/serial_io.c:145