elf.h: add new mips core dump note values from linux v4.19

NT_MIPS_FP_MODE is new in linux commit
1ae22a0e35636efceab83728ba30b013df761592

NT_MIPS_DSP is new in linux commit
44109c60176ae73924a42a6bef64ef151aba9095

include/elf.h

@@ -686,6 +686,8 @@ typedef struct {
 #define NT_METAG_TLS	0x502
 #define NT_ARC_V2	0x600
 #define NT_VMCOREDD	0x700
+#define NT_MIPS_DSP	0x800
+#define NT_MIPS_FP_MODE	0x801
 #define NT_VERSION	1