Bluetooth: ath3k: Use GFP_KERNEL instead of GFP_ATOMIC

We are allowed to sleep here so no need to use GFP_ATOMIC. The caller
(ath3k_probe) calls request_firmware() which definitely sleeps. Hence, we should
avoid using GFP_ATOMIC.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>