[BEETLE] Mbed SDK Init Update

In Beetle systems eFlash and Cache Flash are always enabled by default.
This patch updates the Mbed SDK Init procedure to reflect the changes in
the eFlash and Cache Flash Drivers provided in a previous patch.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

hal/targets/hal/TARGET_ARM_SSG/TARGET_BEETLE/mbed_sdk_init.c

@@ -20,10 +20,11 @@ void mbed_sdk_init(void) {
     SystemPowerConfig();
 
     /* Config EFlash Controller Clock */
-    EFlash_Initialize();
+    EFlash_DriverInitialize();
+    EFlash_ClockConfig();
 
-    /* Initialize Flash Cache */
-    FCache_Initialize();
+    /* Enable Flash Cache Stats */
+    FCache_DriverInitialize();
     FCache_Enable(1);
     FCache_Invalidate();
 }