powerpc/8xx: DEBUG_PAGEALLOC doesn't require an ITLB miss exception handler

Since commit e611939f ("powerpc/mm: Ensure change_page_attr()
doesn't invalidate pinned TLBs"), pinned TLBs are not anymore
invalidated by __kernel_map_pages() when CONFIG_DEBUG_PAGEALLOC is
selected.

Remove the dependency on CONFIG_DEBUG_PAGEALLOC.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e796c5fcb5898de827c803cf1ab8ba1d7a5d4b76.1606231483.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/head_8xx.S

@@ -47,8 +47,7 @@
  * - Either we have modules
  * - Or we have not pinned the first 8M
  */
-#if defined(CONFIG_MODULES) || !defined(CONFIG_PIN_TLB_TEXT) || \
-    defined(CONFIG_DEBUG_PAGEALLOC)
+#if defined(CONFIG_MODULES) || !defined(CONFIG_PIN_TLB_TEXT)
 #define ITLB_MISS_KERNEL	1
 #endif