K64F: Add page allocator sections to linker script

These changes are backwards compatible.

Targets that do not use the page allocator heap will have the same stack
and heap sizes available.

Author: AlessandroA

hal/targets/cmsis/TARGET_Freescale/TARGET_K64F/TOOLCHAIN_GCC_ARM/MK64FN1M0xxx12.ld

@@ -311,18 +311,29 @@ SECTIONS
   .heap :
   {
     . = ALIGN(8);
+    __uvisor_heap_start = .;
     __end__ = .;
     PROVIDE(end = .);
     __HeapBase = .;
     . += HEAP_SIZE;
     __HeapLimit = .;
     __heap_limit = .; /* Add for _sbrk */
+    __uvisor_heap_end = .;
   } > m_data_2
 
   .stack :
   {
     . = ALIGN(8);
     . += STACK_SIZE;
+    __StackTop = .;
+  } > m_data_2
+
+  /* Heap space for the page allocator */
+  .page_heap (NOLOAD) :
+  {
+    __uvisor_page_start = .;
+    . = ORIGIN(m_data_2) + LENGTH(m_data_2) - 4;
+    __uvisor_page_end = .;
   } > m_data_2
 
   m_usb_bdt USB_RAM_START (NOLOAD) :
@@ -337,7 +348,6 @@ SECTIONS
   }
 
   /* Initializes stack on the end of block */
-  __StackTop   = ORIGIN(m_data_2) + LENGTH(m_data_2);
   __StackLimit = __StackTop - STACK_SIZE;
   PROVIDE(__stack = __StackTop);