Correct typographical errors

Corrects typos in core code, documentation files, drivers, Arm
platforms and services.

None of the corrections affect code; changes are limited to comments
and other documentation.

Change-Id: I5c1027b06ef149864f315ccc0ea473e2a16bfd1d
Signed-off-by: Paul Beesley <paul.beesley@arm.com>
diff --git a/plat/arm/common/tsp/arm_tsp_setup.c b/plat/arm/common/tsp/arm_tsp_setup.c
index a3d2f71..e41bfd3 100644
--- a/plat/arm/common/tsp/arm_tsp_setup.c
+++ b/plat/arm/common/tsp/arm_tsp_setup.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -78,7 +78,7 @@
 void tsp_plat_arch_setup(void)
 {
 #if USE_COHERENT_MEM
-	/* Ensure ARM platforms dont use coherent memory in TSP */
+	/* Ensure ARM platforms don't use coherent memory in TSP */
 	assert((BL_COHERENT_RAM_END - BL_COHERENT_RAM_BASE) == 0U);
 #endif