Minor changes to documentation and comments

Fix some typos and clarify some sentences.

Change-Id: Id276d1ced9a991b4eddc5c47ad9a825e6b29ef74
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 819abcd..be84f77 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -140,8 +140,7 @@
 # The platform Makefile is free to override this value.
 PROGRAMMABLE_RESET_ADDRESS	:= 0
 
-# Flag used to choose the power state format viz Extended State-ID or the
-# Original format.
+# Flag used to choose the power state format: Extended State-ID or Original
 PSCI_EXTENDED_STATE_ID		:= 0
 
 # Enable RAS support