mmc: remove hc_wp_grp_size from struct mmc if not needed

hc_wp_grp_size is needed only if hardware partitionning is used.
On ARM removing it saves about 30 bytes of code space.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
diff --git a/cmd/mmc.c b/cmd/mmc.c
index 65601d8..58fdc36 100644
--- a/cmd/mmc.c
+++ b/cmd/mmc.c
@@ -54,8 +54,10 @@
 		bool has_enh = (mmc->part_support & ENHNCD_SUPPORT) != 0;
 		bool usr_enh = has_enh && (mmc->part_attr & EXT_CSD_ENH_USR);
 
+#if CONFIG_IS_ENABLED(MMC_HW_PARTITIONING)
 		puts("HC WP Group Size: ");
 		print_size(((u64)mmc->hc_wp_grp_size) << 9, "\n");
+#endif
 
 		puts("User Capacity: ");
 		print_size(mmc->capacity_user, usr_enh ? " ENH" : "");