Fix build issues for musl libc (#267)

Change-Id: Ia31330b0f96669966712b58986abeca754c2cbb9

libhsakmt/src/libhsakmt.h

@@ -64,14 +64,15 @@ extern HsaVersionInfo hsakmt_kfd_version_info;
 	do { if ((minor) > hsakmt_kfd_version_info.KernelInterfaceMinorVersion)\
 		return HSAKMT_STATUS_NOT_SUPPORTED; } while (0)
 
+extern int hsakmt_page_size;
+extern int hsakmt_page_shift;
+
 /* Might be defined in limits.h on platforms where it is constant (used by musl) */
 /* See also: https://pubs.opengroup.org/onlinepubs/7908799/xsh/limits.h.html */
 #ifndef PAGE_SIZE
-extern int hsakmt_page_size;
 #define PAGE_SIZE hsakmt_page_size
 #endif
 #ifndef PAGE_SHIFT
-extern int hsakmt_page_shift;
 #define PAGE_SHIFT hsakmt_page_shift
 #endif