Rename sha1.c and sha1.h to mesa-sha1.c and mesa-sha1.h

The filename of sha1.h was conflicting with the system-provided
sha1.h, (and in some confiurations, our sha1.c was unsuccessfully
attemping to include "sha1.h" and <sha1.h> as two different files).

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88523

src/util/Makefile.sources

@@ -1,6 +1,6 @@
 MESA_UTIL_SHADER_CACHE_FILES := \
-	sha1.c \
-	sha1.h
+	mesa-sha1.c \
+	mesa-sha1.h
 
 MESA_UTIL_FILES :=	\
 	format_srgb.h \

src/util/mesa-sha1.c

@@ -24,7 +24,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
-#include "sha1.h"
+#include "mesa-sha1.h"
 
 #if defined(HAVE_SHA1_IN_LIBMD)  /* Use libmd for SHA1 */ \
 	|| defined(HAVE_SHA1_IN_LIBC)   /* Use libc for SHA1 */