sfxge(4): fix warnings from VS2015 C compiler (C4214)

[arybchik]

Summary

Fix multiple level 4 warnings
"C4214: nonstandard extension used: bit field types other than int";
no functional changes.

Submitted by: Andrew Lee <alee at solarflare.com>
Sponsored by: Solarflare Communications, Inc.
MFC after: 1 week

Test Plan

amd64 tinderbox kernel builds tested
driver loaded/unloaded, interfaces up/down, traffic works fine

head/sys/dev/sfxge/common/efx.h

 /* firmware activation without reset */
 #define NVME_CTRLR_DATA_FRMW_ACT_WO_RESET_SHIFT         (4)
 #define NVME_CTRLR_DATA_FRMW_ACT_WO_RESET_MASK          (0x1)
 
 /** log page attributes */
 /* per namespace smart/health log page */
 #define NVME_CTRLR_DATA_LPA_NS_SMART_SHIFT              (0)
 #define NVME_CTRLR_DATA_LPA_NS_SMART_MASK               (0x1)
+/* extended data for Get Log Page command */
+#define NVME_CTRLR_DATA_LPA_EXT_DATA_SHIFT              (2)
+#define NVME_CTRLR_DATA_LPA_EXT_DATA_MASK               (0x1)
 
 /** AVSCC - admin vendor specific command configuration */
 /* admin vendor specific commands use spec format */
 #define NVME_CTRLR_DATA_AVSCC_SPEC_FORMAT_SHIFT         (0)
 #define NVME_CTRLR_DATA_AVSCC_SPEC_FORMAT_MASK          (0x1)
 
 /** Autonomous Power State Transition Attributes */
 /* Autonomous Power State Transitions supported */