xfree86: os-support: unexport DEV_MEM defines

DEV_MEM define isn't used by any drivers, and BSD seems to be the only one
left using that define (Linux uses the symbol, but defines on its own)

Therefore, just define it where actually used and drop it from the global
xf86OSlib.h file.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1411>

hw/xfree86/os-support/bsd/alpha_video.c

@@ -42,6 +42,8 @@
 #include "xf86_os_support.h"
 #include "xf86_OSlib.h"
 
+#define DEV_MEM "/dev/mem"
+
 #if defined(__NetBSD__) && !defined(MAP_FILE)
 #define MAP_FLAGS MAP_SHARED
 #else

hw/xfree86/os-support/bsd/arm_video.c

@@ -70,6 +70,8 @@
 #include "xf86_OSlib.h"
 #include "compiler.h"
 
+#define DEV_MEM "/dev/mem"
+
 #if defined(__NetBSD__) && !defined(MAP_FILE)
 #define MAP_FLAGS MAP_SHARED
 #else

hw/xfree86/os-support/bsd/i386_video.c

@@ -40,6 +40,8 @@
 #include <machine/sysarch.h>
 #endif
 
+#define DEV_MEM "/dev/mem"
+
 #if defined(__NetBSD__) && !defined(MAP_FILE)
 #define MAP_FLAGS MAP_SHARED
 #else

hw/xfree86/os-support/xf86_OSlib.h

@@ -230,10 +230,6 @@ struct pcvtid {
 
 #include <limits.h>
 
-#ifndef DEV_MEM
-#define DEV_MEM "/dev/mem"
-#endif
-
 #ifndef MAP_FAILED
 #define MAP_FAILED ((void *)-1)
 #endif