bt-power: Check chip type first before BT resetting

As BT reset only is needed for qca6174 chip, so check chip
type first to avoid triggering get_bt_reset_gpio_value()
for other chip.

CRs-Fixed: 2514357
Change-Id: Icaaf7046aa02d3ae3ecb5bf565cc94c89f11fb71
Signed-off-by: Junlin Zhang <junlzhan@codeaurora.org>