e1000e: increase Rx PBA to prevent dropping received packets on 82566/82567

During bi-directional stress on some 82566/82567 devices, some received
packets were dropped.  Increasing the Receive Packet Buffer Allocation
resolves this.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/e1000e/ich8lan.c

@@ -4108,7 +4108,7 @@ const struct e1000_info e1000_ich9_info = {
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_FLASH
 				  | FLAG_APME_IN_WUC,
-	.pba			= 10,
+	.pba			= 18,
 	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_ich8lan,
 	.mac_ops		= &ich8_mac_ops,
@@ -4125,7 +4125,7 @@ const struct e1000_info e1000_ich10_info = {
 				  | FLAG_HAS_AMT
 				  | FLAG_HAS_FLASH
 				  | FLAG_APME_IN_WUC,
-	.pba			= 10,
+	.pba			= 18,
 	.max_hw_frame_size	= DEFAULT_JUMBO,
 	.get_variants		= e1000_get_variants_ich8lan,
 	.mac_ops		= &ich8_mac_ops,