powerpc/nohash: Remove DEBUG_CLAMP_LAST_CONTEXT

DEBUG_CLAMP_LAST_CONTEXT was there in the old days to reduce
number of contexts in order to ease debugging implementation
of context switching, but that's been quite stable during
years now.

As it is not user selectable, remove it.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/da81837b452e8b9f1657b529b9c3050dc10b9770.1622712515.git.christophe.leroy@csgroup.eu

arch/powerpc/mm/nohash/mmu_context.c

@@ -21,7 +21,6 @@
  *     also clear mm->cpu_vm_mask bits when processes are migrated
  */
 
-//#define DEBUG_CLAMP_LAST_CONTEXT   31
 //#define DEBUG_HARDER
 
 /* We don't use DEBUG because it tends to be compiled in always nowadays
@@ -74,9 +73,7 @@ void *abatron_pteptrs[2];
  * -- BenH
  */
 #define FIRST_CONTEXT 1
-#ifdef DEBUG_CLAMP_LAST_CONTEXT
-#define LAST_CONTEXT DEBUG_CLAMP_LAST_CONTEXT
-#elif defined(CONFIG_PPC_8xx)
+#if defined(CONFIG_PPC_8xx)
 #define LAST_CONTEXT 16
 #elif defined(CONFIG_PPC_47x)
 #define LAST_CONTEXT 65535