i2c: bcm2835: Replace HTTP links with HTTPS ones

Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
[wsa: shortened commit message]
Signed-off-by: Wolfram Sang <wsa@kernel.org>