libcamera: utils: Add strlcpy

strlcpy is available in libbsd, bionic, musl, and ulibc, but not in glibc.
Instead of checking for strlcpy availability and modifying dependencies,
implement it in utils, as a wrapper around strncpy.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/include/utils.h

@@ -12,6 +12,7 @@
 #include <memory>
 #include <ostream>
 #include <string>
+#include <string.h>
 #include <sys/time.h>
 
 #define ARRAY_SIZE(a)	(sizeof(a) / sizeof(a[0]))
@@ -112,6 +113,8 @@ inline _hex hex<uint64_t>(uint64_t value, unsigned int width)
 }
 #endif
 
+size_t strlcpy(char *dst, const char *src, size_t size);
+
 } /* namespace utils */
 
 } /* namespace libcamera */