memalign is Linux-specific, so use C11 aligned_alloc instead

In file included from cmrtlib/agnostic/share/cm_printf_host.cpp:25:
In file included from cmrtlib/linux/../agnostic/share/cm_debug.h:26:
In file included from cmrtlib/linux/../linux/share/cm_def_os.h:37:
/usr/include/malloc.h:3:2: error: "<malloc.h> has been replaced by <stdlib.h>"
#error "<malloc.h> has been replaced by <stdlib.h>"
 ^
In file included from cmrtlib/agnostic/share/cm_printf_host.cpp:25:
In file included from cmrtlib/linux/../agnostic/share/cm_debug.h:26:
cmrtlib/linux/../linux/share/cm_def_os.h:94:10: error: use of undeclared identifier 'memalign'
  return memalign(alignment, size);
         ^
In file included from media_driver/agnostic/gen9_skl/codec/hal/codechal_fei_hevc_g9_skl.cpp:27:
In file included from media_driver/agnostic/gen9_skl/codec/hal/codechal_fei_hevc_g9_skl.h:35:
In file included from media_driver/agnostic/gen9_skl/codec/cmrt_kernel/CMRTKernel_header_file.h:30:
In file included from media_driver/agnostic/gen9_skl/codec/cmrt_kernel/CMRTKernel_DownScaling.h:30:
In file included from media_driver/agnostic/gen9_skl/codec/cmrt_kernel/CMRTKernelBase.h:33:
In file included from /usr/local/include/igfxcmrt/cm_rt.h:185:
In file included from /usr/local/include/igfxcmrt/cm_rt_def_os.h:39:
/usr/include/malloc.h:3:2: error: "<malloc.h> has been replaced by <stdlib.h>"
#error "<malloc.h> has been replaced by <stdlib.h>"
 ^
/usr/local/include/igfxcmrt/cm_rt_def_os.h:153:10: error: use of undeclared identifier 'memalign'
  return memalign(alignment, size);
         ^

--- linux/share/cm_def_os.h.orig	2019-08-29 07:26:40 UTC
+++ linux/share/cm_def_os.h
@@ -32,9 +32,9 @@
 #define Display unsigned int
 #endif
 
+#include <cstdlib>
 #include <cstring>
 #include "pthread.h"
-#include <malloc.h>
 
 
 ////////////////////////////////////////////////////////////////////////////////////
@@ -91,7 +91,7 @@ typedef enum _VACMTEXTUREFILTERTYPE {
 
 inline void * CM_ALIGNED_MALLOC(size_t size, size_t alignment)
 {
-  return memalign(alignment, size);
+  return aligned_alloc(alignment, size);
 }
 
 inline void CM_ALIGNED_FREE(void * memory)
--- linux/share/cm_rt_def_os.h.orig	2018-12-20 08:52:32 UTC
+++ linux/share/cm_rt_def_os.h
@@ -36,7 +36,6 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <math.h>
-#include <malloc.h>
 #include <string.h>
 #include <sys/time.h>
 #include <pthread.h>
@@ -150,7 +149,7 @@ template<> inline const char * CM_TYPE_NAME_UNMANGLED<
 
 inline void * CM_ALIGNED_MALLOC(size_t size, size_t alignment) 
 {
-  return memalign(alignment, size);
+  return aligned_alloc(alignment, size);
 } 
 
 inline void CM_ALIGNED_FREE(void * memory)