Fix two typos.

Signed-off-by: Detlev Zundel <dzu@denx.de>

common/cmd_bootm.c

@@ -466,7 +466,7 @@ U_BOOT_CMD(
  	"\t'arg' can be the address of an initrd image\n"
 #if defined(CONFIG_OF_FLAT_TREE) || defined(CONFIG_OF_LIBFDT)
 	"\tWhen booting a Linux kernel which requires a flat device-tree\n"
-	"\ta third argument is required which is the address of the of the\n"
+	"\ta third argument is required which is the address of the\n"
 	"\tdevice-tree blob. To boot that kernel without an initrd image,\n"
 	"\tuse a '-' for the second argument. If you do not pass a third\n"
 	"\ta bd_info struct will be passed instead\n"

common/cmd_dtt.c

@@ -57,7 +57,7 @@ int do_dtt (cmd_tbl_t * cmdtp, int flag, int argc, char *argv[])
 
 U_BOOT_CMD(
 	  dtt,	1,	1,	do_dtt,
-	  "dtt     - Digital Thermometer and Themostat\n",
+	  "dtt     - Digital Thermometer and Thermostat\n",
 	  "        - Read temperature from digital thermometer and thermostat.\n"
 );