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/drivers/arm/gic/v2/gicv2_main.c b/drivers/arm/gic/v2/gicv2_main.c
index c5d4fe1..c5bced0 100644
--- a/drivers/arm/gic/v2/gicv2_main.c
+++ b/drivers/arm/gic/v2/gicv2_main.c
@@ -279,8 +279,8 @@
 /*******************************************************************************
  * This function sets the GICv2 target mask pattern for the current PE. The PE
  * target mask is used to translate linear PE index (returned by platform core
- * position) to a bit mask used when targeting interrupts to a PE, viz. when
- * raising SGIs and routing SPIs.
+ * position) to a bit mask used when targeting interrupts to a PE (for example
+ * when raising SGIs and routing SPIs).
  ******************************************************************************/
 void gicv2_set_pe_target_mask(unsigned int proc_num)
 {