device ram size is 40 kb, not 48 kB (#128)

* device ram size is 40 kb, not 48 kB
in total RAM+RAM1 it has 48 kB, but the regions are not continous.
This error is also arm-pack index.json

* add section for CCM

targets/TARGET_STM/TARGET_STM32F3/TARGET_STM32F303xC/TOOLCHAIN_GCC_ARM/STM32F303XC.ld

@@ -39,6 +39,7 @@ MEMORY
 {
     FLASH (rx)    : ORIGIN = MBED_APP_START, LENGTH = MBED_APP_SIZE
     RAM (rwx)     : ORIGIN = MBED_RAM_START + VECTORS_SIZE, LENGTH = MBED_RAM_SIZE - VECTORS_SIZE
+    RAM_CCM (rwx) : ORIGIN = MBED_RAM1_START, LENGTH = MBED_RAM1_SIZE
 }
 
 /* Linker script to place sections and symbol values. Should be used together
@@ -183,6 +184,15 @@ SECTIONS
         __HeapLimit = .;
     } > RAM
 
+   .ram_ccm_section  (NOLOAD):
+    { 
+        __ram_ccm_start__ = .;
+        *(.RAM_CCM_section) 
+        . = ORIGIN(RAM_CCM) + LENGTH(RAM_CCM);
+        __ram_ccm_end__ = .;
+    } >RAM_CCM
+
+ 
     /* .stack_dummy section doesn't contains any symbols. It is only
      * used for linker to calculate size of stack sections, and assign
      * values to stack symbols later */

targets/TARGET_STM/TARGET_STM32F3/TARGET_STM32F303xC/cmsis_nvic.h

@@ -30,7 +30,7 @@
 #endif
 
 #if !defined(MBED_RAM_SIZE)
-#define MBED_RAM_SIZE  0xc000  // 48 KB
+#define MBED_RAM_SIZE  0xa000  // 40 KB
 #endif
 
 #if !defined(MBED_RAM1_START)