pnmtohex: Add netpbm to include search patch

Netpbm on Fedora 36 comes without pkg-config, so
manually add the include path.

Signed-off-by: Helge Deller <deller@gmx.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/r/ZCLbduJjX0KS/kJx@ls3530
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
diff --git a/pnmtohex/Makefile b/pnmtohex/Makefile
index 642a26f..d8925a9 100644
--- a/pnmtohex/Makefile
+++ b/pnmtohex/Makefile
@@ -4,6 +4,7 @@
 HOST_TARGET = pnmtohex
 
 CFLAGS += $(shell pkg-config --exists netpbm && pkg-config --cflags netpbm)
+CFLAGS += -I/usr/include/netpbm
 
 # Modern distro's (e.g. Debian, Fedora Core) seem to have -lnetpbm only
 #LIBS += -lnetpnm -lnetpbm -lnetpgm -lnetppm