e1000e: fix legacy interrupt handling in i219

This fix handles a hardware issue that prevented i219 from
working in legacy interrupts mode (IntMode=0)

Signed-off-by: Yanir Lubetkin <yanirx.lubetkin@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/regs.h

@@ -38,6 +38,7 @@
 #define E1000_FEXTNVM4	0x00024	/* Future Extended NVM 4 - RW */
 #define E1000_FEXTNVM6	0x00010	/* Future Extended NVM 6 - RW */
 #define E1000_FEXTNVM7	0x000E4	/* Future Extended NVM 7 - RW */
+#define E1000_FEXTNVM9	0x5BB4  /* Future Extended NVM 9 - RW */
 #define E1000_FEXTNVM11	0x5BBC  /* Future Extended NVM 11 - RW */
 #define E1000_PCIEANACFG	0x00F18	/* PCIE Analog Config */
 #define E1000_FCT	0x00030	/* Flow Control Type - RW */