xen/arm: Remove unused BOOT_RELOC_VIRT_START

We stopped relocating Xen since commit f60658c6ae "xen/arm: Stop
relocating Xen".

At the same time, update the memory layout description.

Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@arm.com>

xen/arch/arm/include/asm/config.h

@@ -77,8 +77,7 @@
  *   2M -   4M   Xen text, data, bss
  *   4M -   6M   Fixmap: special-purpose 4K mapping slots
  *   6M -  10M   Early boot mapping of FDT
- *   10M - 12M   Early relocation address (used when relocating Xen)
- *               and later for livepatch vmap (if compiled in)
+ *   10M - 12M   Livepatch vmap (if compiled in)
  *
  * ARM32 layout:
  *   0  -  12M   <COMMON>
@@ -115,7 +114,6 @@
 #define BOOT_FDT_SLOT_SIZE     MB(4)
 #define BOOT_FDT_VIRT_END      (BOOT_FDT_VIRT_START + BOOT_FDT_SLOT_SIZE)
 
-#define BOOT_RELOC_VIRT_START  _AT(vaddr_t,0x00a00000)
 #ifdef CONFIG_LIVEPATCH
 #define LIVEPATCH_VMAP_START   _AT(vaddr_t,0x00a00000)
 #define LIVEPATCH_VMAP_END     (LIVEPATCH_VMAP_START + MB(2))

xen/arch/arm/mm.c

@@ -196,7 +196,6 @@ static void __init __maybe_unused build_assertions(void)
     /* 2MB aligned regions */
     BUILD_BUG_ON(XEN_VIRT_START & ~SECOND_MASK);
     BUILD_BUG_ON(FIXMAP_ADDR(0) & ~SECOND_MASK);
-    BUILD_BUG_ON(BOOT_RELOC_VIRT_START & ~SECOND_MASK);
     /* 1GB aligned regions */
 #ifdef CONFIG_ARM_32
     BUILD_BUG_ON(XENHEAP_VIRT_START & ~FIRST_MASK);