bl2_el3: clean up linker script

This linker script is so unreadable due to sprinkled #ifdef.

Direct read-only data to 'ROM' and read-write data to 'RAM'.

Both go to the same memory device when BL2_IN_XIP_MEM is disabled.

Change-Id: Ieeac3f1a4e05e9e8599de2ec84260819c70f361e
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

bl2/bl2_el3.ld.S

@@ -21,6 +21,9 @@ MEMORY {
 #endif
 }
 
+#if !BL2_IN_XIP_MEM
+#define ROM RAM
+#endif
 
 SECTIONS
 {
@@ -45,11 +48,7 @@ SECTIONS
         *(.vectors)
         . = ALIGN(PAGE_SIZE);
         __TEXT_END__ = .;
-#if BL2_IN_XIP_MEM
      } >ROM
-#else
-     } >RAM
-#endif
 
     .rodata . : {
         __RODATA_START__ = .;
@@ -72,11 +71,7 @@ SECTIONS
 
         . = ALIGN(PAGE_SIZE);
         __RODATA_END__ = .;
-#if BL2_IN_XIP_MEM
     } >ROM
-#else
-    } >RAM
-#endif
 
     ASSERT(__TEXT_RESIDENT_END__ - __TEXT_RESIDENT_START__ <= PAGE_SIZE,
           "Resident part of BL2 has exceeded its limit.")
@@ -115,11 +110,7 @@ SECTIONS
         . = ALIGN(PAGE_SIZE);
 
         __RO_END__ = .;
-#if BL2_IN_XIP_MEM
     } >ROM
-#else
-    } >RAM
-#endif
 #endif
 
     ASSERT(__CPU_OPS_END__ > __CPU_OPS_START__,
@@ -146,11 +137,7 @@ SECTIONS
         __DATA_RAM_START__ = .;
         *(.data*)
         __DATA_RAM_END__ = .;
-#if BL2_IN_XIP_MEM
     } >RAM AT>ROM
-#else
-    } >RAM
-#endif
 
     stacks (NOLOAD) : {
         __STACKS_START__ = .;