Move SEEK_xxx from unistd.h to sys/types.h

so fcntl.h, stdio.h and unistd.h could get these definiton:
https://en.cppreference.com/w/c/io/fseek
https://pubs.opengroup.org/onlinepubs/7908799/xsh/fcntl.html
https://pubs.opengroup.org/onlinepubs/007904975/functions/lseek.html

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

include/sys/types.h

@@ -60,6 +60,12 @@
 #  endif
 #endif
 
+/* Values for seeking */
+
+#define SEEK_SET    0  /* From the start of the file */
+#define SEEK_CUR    1  /* From the current file offset */
+#define SEEK_END    2  /* From the end of the file */
+
 #ifndef CONFIG_SMP_NCPUS
 #  define CONFIG_SMP_NCPUS 1
 #endif

include/unistd.h

@@ -33,12 +33,6 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-/* Values for seeking */
-
-#define SEEK_SET    0  /* From the start of the file */
-#define SEEK_CUR    1  /* From the current file offset */
-#define SEEK_END    2  /* From the end of the file */
-
 /* Bit values for the second argument to access */
 
 #define F_OK        0  /* Test existence */