opkg: upgrade 0.6.1 -> 0.6.2

opkg: upgrade 0.6.1 -> 0.6.2

0001-Define-alignof-using-_Alignof-when-using-C11-or-newe.patch
0002-opkg-key-remove-no-options-flag-from-gpg-calls.patch
removed since they're included in 0.6.2.

Changelog:
===========
### Changed
- the project's developer documentation to be more correct and current.

### Fixed
- a bug in the 'opkg-keys' utility script which caused the script to ignore settings in the '/etc/opkg/gpg/gpg.conf' file.
- a compilation error in 'md5.c' when using clang16+ and '-std >= gnu11'.

Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>