Bluetooth: Don't use cmd_timer to timeout HCI reset command

No command should be send before Command Complete event for HCI
reset is received. This fix regression introduced by commit
6bd32326(Bluetooth: Use proper timer for hci command timout)
for chips whose reset command takes longer to complete (e.g. CSR)
resulting in next command being send before HCI reset completed.

Signed-off-by: Szymon Janc <szymon@janc.net.pl>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>