[MIPS] Remove unused system type name for DDB5074 and DDB5476.

This patch removes unused system type name.
DDB5074 and DDB5476 were already removed.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/ddb5xxx/common/prom.c

@@ -21,8 +21,6 @@
 const char *get_system_type(void)
 {
 	switch (mips_machtype) {
-	case MACH_NEC_DDB5074:		return "NEC DDB Vrc-5074";
-	case MACH_NEC_DDB5476:		return "NEC DDB Vrc-5476";
 	case MACH_NEC_DDB5477:		return "NEC DDB Vrc-5477";
 	case MACH_NEC_ROCKHOPPER:	return "NEC Rockhopper";
 	case MACH_NEC_ROCKHOPPERII:     return "NEC RockhopperII";