distrodata: Updated checkpkg task

distrodata: Updated checkpkg task

bitbake -c checkpkg fetches the latest version for all packages,
including the ones from sourceforge and those that have
ununsual package naming.
Also removed all pn-native/nativesdk-pn entries from the resulting
checkpkg.csv file if the system already reported the latest version
for pn.

(From OE-Core rev: dc33d69df55ad8d63024d34e35a0b987e01b0077)

Signed-off-by: Emilia Ciobanu <emilia.maria.silvia.ciobanu@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>