sfc: Const-qualify static data as appropriate, partly prompted by checkpatch

Fix the following warnings:

WARNING: struct dev_pm_ops should normally be const
WARNING: static const char * array should probably be static const char * const

Similarly const-qualify struct i2c_board_info, struct i2c_algo_bit_data,
struct efx_ethtool_stat, struct efx_mtd_ops and struct siena_nvram_type_info.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index 81a4253..b1de400 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -502,7 +502,7 @@
 	efx_link_status_changed(efx);
 }
 
-static const char *sensor_names[] = {
+static const char *const sensor_names[] = {
 	[MC_CMD_SENSOR_CONTROLLER_TEMP] = "Controller temp. sensor",
 	[MC_CMD_SENSOR_PHY_COMMON_TEMP] = "PHY shared temp. sensor",
 	[MC_CMD_SENSOR_CONTROLLER_COOLING] = "Controller cooling",
@@ -518,7 +518,7 @@
 	[MC_CMD_SENSOR_IN_12V0] = "12V supply sensor"
 };
 
-static const char *sensor_status_names[] = {
+static const char *const sensor_status_names[] = {
 	[MC_CMD_SENSOR_STATE_OK] = "OK",
 	[MC_CMD_SENSOR_STATE_WARNING] = "Warning",
 	[MC_CMD_SENSOR_STATE_FATAL] = "Fatal",