x86/mm: Drop unused MAX_PHYSADDR_BITS

The macro is not used anywhere, and has an incorrect value (going by the
comment) on x86_64 since commit c898faf9 ("x86: 46 bit physical address
support on 64 bits")

To avoid confusion, just remove the definition.
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200723231544.17274-2-nivedita@alum.mit.edu

arch/x86/include/asm/sparsemem.h

@@ -10,24 +10,20 @@
  *    field of the struct page
  *
  * SECTION_SIZE_BITS		2^n: size of each section
- * MAX_PHYSADDR_BITS		2^n: max size of physical address space
- * MAX_PHYSMEM_BITS		2^n: how much memory we can have in that space
+ * MAX_PHYSMEM_BITS		2^n: max size of physical address space
  *
  */
 
 #ifdef CONFIG_X86_32
 # ifdef CONFIG_X86_PAE
 #  define SECTION_SIZE_BITS	29
-#  define MAX_PHYSADDR_BITS	36
 #  define MAX_PHYSMEM_BITS	36
 # else
 #  define SECTION_SIZE_BITS	26
-#  define MAX_PHYSADDR_BITS	32
 #  define MAX_PHYSMEM_BITS	32
 # endif
 #else /* CONFIG_X86_32 */
 # define SECTION_SIZE_BITS	27 /* matt - 128 is convenient right now */
-# define MAX_PHYSADDR_BITS	(pgtable_l5_enabled() ? 52 : 44)
 # define MAX_PHYSMEM_BITS	(pgtable_l5_enabled() ? 52 : 46)
 #endif