brcm80211: update the maintainers listed for brcm80211 drivers

Henry Ptasinski is not working on the brcm80211 driver so taking
his name/email out of the MAINTAINERS file.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>