package/tiff: add optional support for xz

When xz was compiled before, tiff will use it as optional dependency:

$ output/host/usr/bin/i586-buildroot-linux-uclibc-readelf -a output/target/usr/lib/libtiff.so.5.2.4 | grep NEEDED
 0x00000001 (NEEDED)                     Shared library: [liblzma.so.5]
 0x00000001 (NEEDED)                     Shared library: [libjpeg.so.9]
 0x00000001 (NEEDED)                     Shared library: [libz.so.1]
 0x00000001 (NEEDED)                     Shared library: [libm.so.1]
 0x00000001 (NEEDED)                     Shared library: [libc.so.1]

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/tiff/Config.in

@@ -41,6 +41,10 @@ config BR2_PACKAGE_TIFF_ZLIB
 	select BR2_PACKAGE_ZLIB
 	default y
 
+config BR2_PACKAGE_TIFF_XZ
+	bool "XZ compression"
+	select BR2_PACKAGE_XZ
+
 config BR2_PACKAGE_TIFF_PIXARLOG
 	bool "Pixar log-format algorithm (requires Zlib)"
 	select BR2_PACKAGE_TIFF_ZLIB

package/tiff/tiff.mk

@@ -49,6 +49,12 @@ else
 TIFF_DEPENDENCIES += zlib
 endif
 
+ifneq ($(BR2_PACKAGE_TIFF_XZ),y)
+TIFF_CONF_OPTS += --disable-lzma
+else
+TIFF_DEPENDENCIES += xz
+endif
+
 ifneq ($(BR2_PACKAGE_TIFF_PIXARLOG),y)
 TIFF_CONF_OPTS += --disable-pixarlog
 endif