fix: clean up Windows timer includes

- Removed legacy GCC-specific include block.
- Added compiler-specific headers:
  - MSVC (_MSC_VER): includes <timeapi.h> and links winmm.lib
  - Other compilers: includes <mmsystem.h>
- Ensures cross-compiler compatibility and avoids duplicate headers.

portable/MSVC-MingW/port.c

@@ -41,16 +41,11 @@
 
 #ifdef _MSC_VER
     #include <timeapi.h>
+    #pragma comment(lib, "winmm.lib")
 #else
     #include <mmsystem.h>
 #endif
 
-#ifdef __GNUC__
-    #include "mmsystem.h"
-#else
-    #pragma comment(lib, "winmm.lib")
-#endif
-
 #define portMAX_INTERRUPTS                          ( ( uint32_t ) sizeof( uint32_t ) * 8UL ) /* The number of bits in an uint32_t. */
 #define portNO_CRITICAL_NESTING                     ( ( uint32_t ) 0 )