arch/Config.in: remove BR2_ARCH_HAS_MMU_MANDATORY from BR2_aarch64*

Selecting BR2_ARCH_HAS_MMU_MANDATORY from BR2_aarch64 and
BR2_aarch64_be doesn't make much sense, because the actual ARM cores
described in arch/Config.in.arm then all select
BR2_ARCH_HAS_MMU_OPTIONAL. So we end up with both
BR2_ARCH_HAS_MMU_OPTIONAL and BR2_ARCH_HAS_MMU_MANDATORY, which
doesn't make any sense.

To prevent this, we remove the selection of BR2_ARCH_HAS_MMU_MANDATORY
from BR2_aarch64 and BR2_aarch64_be, and let arch/Config.in.arm do its
job. What arch/Config.in.arm does is currently incorrect, but it will
be fixed in a separate commit.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

arch/Config.in

@@ -60,7 +60,6 @@ config BR2_armeb
 config BR2_aarch64
 	bool "AArch64 (little endian)"
 	select BR2_ARCH_IS_64
-	select BR2_ARCH_HAS_MMU_MANDATORY
 	help
 	  Aarch64 is a 64-bit architecture developed by ARM Holdings.
 	  http://www.arm.com/products/processors/instruction-set-architectures/armv8-architecture.php
@@ -69,7 +68,6 @@ config BR2_aarch64
 config BR2_aarch64_be
 	bool "AArch64 (big endian)"
 	select BR2_ARCH_IS_64
-	select BR2_ARCH_HAS_MMU_MANDATORY
 	help
 	  Aarch64 is a 64-bit architecture developed by ARM Holdings.
 	  http://www.arm.com/products/processors/instruction-set-architectures/armv8-architecture.php