rtc: at32ap700x: update author email

This patch updates the email address of the rtc-at32ap700x driver supported by
me to an email account I will use on a more regular basis in the future.

Signed-off-by: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>