b43: HT-PHY: rename AFE defines

It you take a look at N-PHY analog switch function it touches every core
on the chipset. It seems HT-PHY does they same, it just has 3 cores
instead of 2 (which make sense since BCM4331 is 3x3). Rename AFE defines
to include core id.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>