cmd: Convert existing long help messages to the new macro

- Generally we just drop the #ifdef CONFIG_SYS_LONGHELP and endif lines
  and use U_BOOT_LONGHELP to declare the same variable name as before
- In a few places, either rename the variable to follow convention or
  introduce the variable as it was being done inline before.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/mtd.c b/cmd/mtd.c
index eb6e2d6..e63c011 100644
--- a/cmd/mtd.c
+++ b/cmd/mtd.c
@@ -541,8 +541,7 @@
 }
 #endif /* CONFIG_AUTO_COMPLETE */
 
-#ifdef CONFIG_SYS_LONGHELP
-static char mtd_help_text[] =
+U_BOOT_LONGHELP(mtd,
 	"- generic operations on memory technology devices\n\n"
 	"mtd list\n"
 	"mtd read[.raw][.oob]                  <name> <addr> [<off> [<size>]]\n"
@@ -563,8 +562,7 @@
 	"\t\t* must be a multiple of a block for erase\n"
 	"\t\t* must be a multiple of a page otherwise (special case: default is a page with dump)\n"
 	"\n"
-	"The .dontskipff option forces writing empty pages, don't use it if unsure.\n";
-#endif
+	"The .dontskipff option forces writing empty pages, don't use it if unsure.\n");
 
 U_BOOT_CMD_WITH_SUBCMDS(mtd, "MTD utils", mtd_help_text,
 		U_BOOT_SUBCMD_MKENT(list, 1, 1, do_mtd_list),