Change email address for 8250_pci

commit f2e0ea861117bda073d1d7ffbd3120c07c0d5d34 upstream.

I'm still receiving reports to my email address, so let's point this
at the linux-serial mailing list instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>