raspberrypi-footer.md: Additional notes
raspberrypi-footer.md: Additional notes

Add notes for the commercial licensed packages
and the screen rotation using the official
Raspberry Pi 7" touchscreeen.

Signed-off-by: Leon Anavi <15d13d7e2c6115f28df053122512bfcb5eb2dbf7@konsulko.com>

automotive-grade-linux/docs-agl,claneys/docs-agl,leon-anavi/docs-agl,automotive-grade-linux/docs-agl,automotive-grade-linux/docs-agl,claneys/docs-agl,claneys/docs-agl,leon-anavi/docs-agl,leon-anavi/docs-agl,claneys/docs-agl,automotive-grade-linux/docs-agl,leon-anavi/docs-agl