libcamera: Fix compilation with uClibc and uClibc-ng

Neither uClibc nor uClibc-ng support O_TMPFILE. Define it in utils.h if
not defined.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>

src/libcamera/include/utils.h

@@ -16,6 +16,15 @@
 
 #define ARRAY_SIZE(a)	(sizeof(a) / sizeof(a[0]))
 
+#ifndef __DOXYGEN__
+
+/* uClibc and uClibc-ng don't provide O_TMPFILE */
+#ifndef O_TMPFILE
+#define O_TMPFILE	(020000000 | O_DIRECTORY)
+#endif
+
+#endif
+
 namespace libcamera {
 
 namespace utils {