lib: package: Replace ":" in file names

The purpose of this translation API is to make sure that the file name
can be used in a bitbake variable without adding special meaning,
therefore the ":" should also be replaced since it is the override
separator

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>