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/mtd.c b/drivers/net/ethernet/sfc/mtd.c
index bc9dcd6..13f61fb 100644
--- a/drivers/net/ethernet/sfc/mtd.c
+++ b/drivers/net/ethernet/sfc/mtd.c
@@ -382,7 +382,7 @@
 	return rc;
 }
 
-static struct efx_mtd_ops falcon_mtd_ops = {
+static const struct efx_mtd_ops falcon_mtd_ops = {
 	.read	= falcon_mtd_read,
 	.erase	= falcon_mtd_erase,
 	.write	= falcon_mtd_write,
@@ -560,7 +560,7 @@
 	return rc;
 }
 
-static struct efx_mtd_ops siena_mtd_ops = {
+static const struct efx_mtd_ops siena_mtd_ops = {
 	.read	= siena_mtd_read,
 	.erase	= siena_mtd_erase,
 	.write	= siena_mtd_write,
@@ -572,7 +572,7 @@
 	const char *name;
 };
 
-static struct siena_nvram_type_info siena_nvram_types[] = {
+static const struct siena_nvram_type_info siena_nvram_types[] = {
 	[MC_CMD_NVRAM_TYPE_DISABLED_CALLISTO]	= { 0, "sfc_dummy_phy" },
 	[MC_CMD_NVRAM_TYPE_MC_FW]		= { 0, "sfc_mcfw" },
 	[MC_CMD_NVRAM_TYPE_MC_FW_BACKUP]	= { 0, "sfc_mcfw_backup" },
@@ -593,7 +593,7 @@
 				     unsigned int type)
 {
 	struct efx_mtd_partition *part = &efx_mtd->part[part_id];
-	struct siena_nvram_type_info *info;
+	const struct siena_nvram_type_info *info;
 	size_t size, erase_size;
 	bool protected;
 	int rc;