Fix violations to the coding style

All coding style violations have been fixed in a previous patch and
since then, each individual patch has been checked in this regard.
However, the latest version of the checkpatch.pl script from the Linux
kernel is more advanced and it is able to flag new errors in the
Trusted Firmware codebase. This patch fixes them.

Change-Id: I1f332f2440984be85d36b231bb83260368987077
diff --git a/plat/fvp/fvp_pm.c b/plat/fvp/fvp_pm.c
index 9044e69..c15d845 100644
--- a/plat/fvp/fvp_pm.c
+++ b/plat/fvp/fvp_pm.c
@@ -64,7 +64,7 @@
  * Function which implements the common FVP specific operations to power down a
  * cpu in response to a CPU_OFF or CPU_SUSPEND request.
  ******************************************************************************/
-static void fvp_cpu_pwrdwn_common()
+static void fvp_cpu_pwrdwn_common(void)
 {
 	/* Prevent interrupts from spuriously waking up this cpu */
 	arm_gic_cpuif_deactivate();
@@ -77,7 +77,7 @@
  * Function which implements the common FVP specific operations to power down a
  * cluster in response to a CPU_OFF or CPU_SUSPEND request.
  ******************************************************************************/
-static void fvp_cluster_pwrdwn_common()
+static void fvp_cluster_pwrdwn_common(void)
 {
 	uint64_t mpidr = read_mpidr_el1();