Fix read_subpkgdata_dict to account for the new override operator being
":" instead of "_"
(From OE-Core rev: 0b04ae769d4fad2caaa858803d8fbbbaec689541)
Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>