qcacmn: Define qdf_mempool_t for non kernel users

Fix implicit declaration error when qdf_mem.h is included from userspace

Change-Id: I88ccec9c53abb8d5844f42984af3f8693c1d3000
CRs-Fixed: 1012511

qdf/linux/src/i_qdf_mem.h

@@ -62,15 +62,7 @@
 #define kfree(buf)
 #define vfree(buf)
 #define pci_alloc_consistent(dev, size, paddr) NULL
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 4, 0)
-/*
- * typedef to dummy type to overcome implicit declaration error in
- * spectraltool.c
- */
-#define __qdf_mempool_t int
-#else
-#define __qdf_mempool_t
-#endif /* LINUX_VERSION_CODE */
+#define __qdf_mempool_t void*
 #endif /* __KERNEL__ */
 #include <qdf_status.h>