bluetooth: Disable MSM 8974 Bluetooth rfkill

Having both HCI core rfkill and MSM 8974 rfkill enabled causes
problems with unblocking BT after it has been blocked. Also, using
only the device-specific rfkill to block and unblock bluetooth leads
to device becoming unresponsive for reasons currently unknown.

For the time being, disable the device-specific rfkill, but power on
the device during initialization.

[bluetooth] Disable MSM 8974 Bluetooth rfkill

Signed-off-by: Hannu Mallat <hannu.mallat@jollamobile.com>