package/btrfs-progs: fix build on kernel < 5.10

zoned depends on kernel >= 5.10:
https://github.com/kdave/btrfs-progs/commit/d4b4baf312ff083fb1e85de92167ea3e968c684c

Fix the following build failure raised since bump to version 5.15.1 in
commit 20181c3f1b7191d2b6a1b78bfbe32c1f58e87359:

checking linux/blkzoned.h usability... yes
checking linux/blkzoned.h presence... yes
checking for linux/blkzoned.h... yes
checking for struct blk_zone.capacity... no
checking for BLKGETZONESZ defined in linux/blkzoned.h... yes
configure: error: linux/blkzoned.h does not provide blk_zone.capacity

Fixes:
 - http://autobuild.buildroot.org/results/381c7e8b4bfa624c3eca3ce072cfa412aba57f84

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/btrfs-progs/btrfs-progs.mk

@@ -44,6 +44,12 @@ else
 BTRFS_PROGS_CONF_OPTS += --disable-libudev
 endif
 
+ifeq ($(BR2_TOOLCHAIN_HEADERS_AT_LEAST_5_10),y)
+BTRFS_PROGS_CONF_OPTS += --enable-zoned
+else
+BTRFS_PROGS_CONF_OPTS += --disable-zoned
+endif
+
 HOST_BTRFS_PROGS_DEPENDENCIES = host-util-linux host-lzo host-zlib
 HOST_BTRFS_PROGS_CONF_OPTS = \
 	--disable-backtrace \