ixgbe: declare ixgbe_mac_operations structures as const

Declare ixgbe_mac_operations structures as const as they are only stored
in the mac_ops field of ixgbe_info structure. This field is of type
const and therefore ixgbe_mac_operations structure can be made const
too.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_x550.c

@@ -3884,7 +3884,7 @@ static const struct ixgbe_mac_operations mac_ops_X550EM_x_fw = {
 	.write_iosf_sb_reg	= ixgbe_write_iosf_sb_reg_x550,
 };
 
-static struct ixgbe_mac_operations mac_ops_x550em_a = {
+static const struct ixgbe_mac_operations mac_ops_x550em_a = {
 	X550_COMMON_MAC
 	.led_on			= ixgbe_led_on_t_x550em,
 	.led_off		= ixgbe_led_off_t_x550em,
@@ -3905,7 +3905,7 @@ static struct ixgbe_mac_operations mac_ops_x550em_a = {
 	.write_iosf_sb_reg	= ixgbe_write_iosf_sb_reg_x550a,
 };
 
-static struct ixgbe_mac_operations mac_ops_x550em_a_fw = {
+static const struct ixgbe_mac_operations mac_ops_x550em_a_fw = {
 	X550_COMMON_MAC
 	.led_on			= ixgbe_led_on_generic,
 	.led_off		= ixgbe_led_off_generic,