ARM: 8952/1: Disable kmemleak on XIP kernels

Kmemleak relies on specific symbols to register the read only data
during init (e.g. __start_ro_after_init).
Trying to build an XIP kernel on arm results in the linking error
reported below because when this option is selected read only data
after init are not allowed since .data is read only (.rodata).

  arm-linux-gnueabihf-ld: mm/kmemleak.o: in function `kmemleak_init':
  kmemleak.c:(.init.text+0x148): undefined reference to `__end_ro_after_init'
  arm-linux-gnueabihf-ld: kmemleak.c:(.init.text+0x14c):
     undefined reference to `__end_ro_after_init'
  arm-linux-gnueabihf-ld: kmemleak.c:(.init.text+0x150):
     undefined reference to `__start_ro_after_init'
  arm-linux-gnueabihf-ld: kmemleak.c:(.init.text+0x156):
     undefined reference to `__start_ro_after_init'
  arm-linux-gnueabihf-ld: kmemleak.c:(.init.text+0x162):
     undefined reference to `__start_ro_after_init'
  arm-linux-gnueabihf-ld: kmemleak.c:(.init.text+0x16a):
     undefined reference to `__start_ro_after_init'
  linux/Makefile:1078: recipe for target 'vmlinux' failed

Fix the issue enabling kmemleak only on non XIP kernels.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/Kconfig

@@ -73,7 +73,7 @@ config ARM
 	select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
 	select HAVE_CONTEXT_TRACKING
 	select HAVE_C_RECORDMCOUNT
-	select HAVE_DEBUG_KMEMLEAK
+	select HAVE_DEBUG_KMEMLEAK if !XIP_KERNEL
 	select HAVE_DMA_CONTIGUOUS if MMU
 	select HAVE_DYNAMIC_FTRACE if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS if HAVE_DYNAMIC_FTRACE