ARM: 8709/1: NOMMU: Disallow MPU for XIP

It seems that MPU never worked with XIP, so we just disallow such
combination.
Tested-by: NSzemző András <sza@esh.hu>
Tested-by: NAlexandre TORGUE <alexandre.torgue@st.com>
Tested-by: NBenjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

arch/arm/Kconfig-nommu

@@ -52,7 +52,7 @@ config REMAP_VECTORS_TO_RAM
 
 config ARM_MPU
        bool 'Use the ARM v7 PMSA Compliant MPU'
-       depends on CPU_V7
+       depends on !XIP_KERNEL && CPU_V7
        default y
        help
          Some ARM systems without an MMU have instead a Memory Protection