qlcnic: Add support for PEX DMA method to read memory section of adapter dump

This patch adds support to read memory section of adapter
dump using PEX DMA method. This method significantly improves
total adapter dump collection time.

Signed-off-by: Shahed Shaikh <shahed.shaikh@qlogic.com>
Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>