make : update MSYS_NT (ggerganov#1813)

I just upgraded the R wrapper at https://github.com/bnosac/audio.whisper to use whisper.cpp 1.5.4
I'm working on Windows and noticed while doing that that it did not pick up the relevant CFLAGS/CXXFLAGS as my system showed

```
I whisper.cpp build info: 
I UNAME_S:  MSYS_NT-10.0-19045
I UNAME_P:  unknown
I UNAME_M:  x86_64
```

Many thanks for all the tremendous hard work on maintaining whisper.cpp!

Makefile

@@ -117,7 +117,7 @@ ifeq ($(UNAME_M),$(filter $(UNAME_M),x86_64 i686 amd64))
  CPUINFO_CMD := sysctl machdep.cpu.features machdep.cpu.leaf7_features
  else ifeq ($(UNAME_S),Linux)
  CPUINFO_CMD := cat /proc/cpuinfo
- else ifneq (,$(filter MINGW32_NT% MINGW64_NT%,$(UNAME_S)))
+ else ifneq (,$(filter MINGW32_NT% MINGW64_NT% MSYS_NT%,$(UNAME_S)))
  CPUINFO_CMD := cat /proc/cpuinfo
  else ifneq (,$(filter DragonFly FreeBSD,$(UNAME_S)))
  CPUINFO_CMD := grep Features /var/run/dmesg.boot