optee-client: use /var/lib/tee instead of /data/tee for persistent storage

This is more FHS-conformant, and allows tee-supplicant to work on a
readonly rootfs setup (although then it uses volatile storage by
default, and it is still a matter of distro policy how to arrange for
that storage to be persistent in a readonly setup).

Signed-off-by: Yann Dirson <yann@blade-group.com>
Suggested-by: Ricardo Salveti <ricardo@foundries.io>
Signed-off-by: Jon Mason <jon.mason@arm.com>

meta-arm/recipes-security/optee/optee-client.inc

@@ -17,7 +17,10 @@ UPSTREAM_CHECK_GITTAGREGEX = "^(?P<pver>\d+(\.\d+)+)$"
 
 S = "${WORKDIR}/git"
 
-EXTRA_OECMAKE = "-DBUILD_SHARED_LIBS=ON"
+EXTRA_OECMAKE = " \
+    -DBUILD_SHARED_LIBS=ON \
+    -DCFG_TEE_FS_PARENT_PATH='${localstatedir}/lib/tee' \
+"
 EXTRA_OECMAKE_append_toolchain-clang = " -DCFG_WERROR=0"
 
 do_install_append() {