bna: Flash controller ioc pll init fixes

Added NFC pause/resume logic. We only do NFC pause/resume if NFC version
is greater than 0x143 and it was halted before, otherwise we revert to
old NFC halt mechanism.

Made changes to avoid clearing off the interrupts during the initial
pll initialization.

Signed-off-by: Jing Huang <huangj@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>