backports: fix compilation with CONFIG_OF

There are two users of of_find_property_value_of_size() which is
originally static in the kernel, but we need it exposed (but not
exported) so that multiple backport files can use it; do that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
3 files changed