cnss: Fix pcie link down recovery issue

Reset pci link down indication flag. Do not restore in recovery
case. Don't disable irq for QCA6290 during recovery as it is
shared with MHI.

CRs-Fixed: 2011578
Change-Id: Ib0e6ca29d745cdeb5022c047bb437d2d9d010ce8
Signed-off-by: Yuanyuan Liu <yuanliu@codeaurora.org>