ice: Update Boot Configuration Section read of NVM

The Boot Configuration Section Block has been moved to the Preserved Field
Area (PFA) of NVM. Update the NVM reads that involves Boot Configuration
Section.

Signed-off-by: Md Fahad Iqbal Polash <md.fahad.iqbal.polash@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>