mmc: Remove hwpartition help text when command is disabled

When the `mmc hwpartition` command is disabled, remove the associated help
text.

Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>

cmd/mmc.c

@@ -935,6 +935,7 @@ U_BOOT_CMD(
 	"mmc part - lists available partition on current mmc device\n"
 	"mmc dev [dev] [part] - show or set current mmc device [partition]\n"
 	"mmc list - lists available devices\n"
+#if CONFIG_IS_ENABLED(MMC_HW_PARTITIONING)
 	"mmc hwpartition [args...] - does hardware partitioning\n"
 	"  arguments (sizes in 512-byte blocks):\n"
 	"    [user [enh start cnt] [wrrel {on|off}]] - sets user data area attributes\n"
@@ -942,6 +943,7 @@ U_BOOT_CMD(
 	"    [check|set|complete] - mode, complete set partitioning completed\n"
 	"  WARNING: Partitioning is a write-once setting once it is set to complete.\n"
 	"  Power cycling is required to initialize partitions after set to complete.\n"
+#endif
 #ifdef CONFIG_SUPPORT_EMMC_BOOT
 	"mmc bootbus dev boot_bus_width reset_boot_bus_width boot_mode\n"
 	" - Set the BOOT_BUS_WIDTH field of the specified device\n"