gd: Add patch to fix compiler error about missing const

Gcc complains about:

| ../../sources/gd-2.3.3/src/gd_filename.c: In function 'ftype':
| ../../sources/gd-2.3.3/src/gd_filename.c:99:9: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
|    99 |     ext = strrchr(filename, '.');
|       |         ^
| cc1: all warnings being treated as errors

Even the newest git master commit does not fix this.

Signed-off-by: Jörg Sommer <joerg.sommer@navimatix.de>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/gd/gd/Fix-ftype-missing-const.patch

@@ -0,0 +1,23 @@
+gcc complains about
+
+| ../../sources/gd-2.3.3/src/gd_filename.c: In function 'ftype':
+| ../../sources/gd-2.3.3/src/gd_filename.c:99:9: error: assignment discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers]
+|    99 |     ext = strrchr(filename, '.');
+|       |         ^
+| cc1: all warnings being treated as errors
+
+Upstream-Status: Submitted [https://github.com/libgd/libgd/issues/985]
+
+diff --git i/src/gd_filename.c w/src/gd_filename.c
+index 7ce4817f..89b25204 100644
+--- i/src/gd_filename.c
++++ w/src/gd_filename.c
+@@ -93,7 +93,7 @@ static const struct FileType {
+ static const struct FileType *
+ ftype(const char *filename) {
+     int n;
+-    char *ext;
++    const char *ext;
+
+     /* Find the file extension (i.e. the last period in the string. */
+     ext = strrchr(filename, '.');

meta-oe/recipes-support/gd/gd_2.3.3.bb

@@ -15,6 +15,7 @@ DEPENDS = "freetype libpng jpeg zlib tiff"
 
 SRC_URI = "git://github.com/libgd/libgd.git;nobranch=1;protocol=https \
            file://0001-Fix-deprecared-function-prototypes.patch \
+           file://Fix-ftype-missing-const.patch \
            "
 
 SRCREV = "b5319a41286107b53daa0e08e402aa1819764bdc"