arm, tests: Update config files to more recent kernels and create 64-bit regressions.

This changes the default ARM system to a Versatile Express-like system that supports
2GB of memory and PCI devices and updates the default kernels/file-systems for
AArch64 ARM systems (64-bit) to support up to 32GB of memory and PCI devices. Some
platforms that are no longer supported have been pruned from the configuration files.

In addition a set of 64-bit ARM regressions have been added to the regression system.

src/arch/arm/ArmSystem.py

@@ -42,8 +42,6 @@ from System import System
 class ArmMachineType(Enum):
     map = {'RealView_EB' : 827,
            'RealView_PBX' : 1901,
-           'VExpress_ELT' : 2272,
-           'VExpress_CA9' : 2272,
            'VExpress_EMM' : 2272,
            'VExpress_EMM64' : 2272}
 
@@ -77,7 +75,7 @@ class LinuxArmSystem(ArmSystem):
     type = 'LinuxArmSystem'
     cxx_header = "arch/arm/linux/system.hh"
     load_addr_mask = 0x0fffffff
-    machine_type = Param.ArmMachineType('RealView_PBX',
+    machine_type = Param.ArmMachineType('VExpress_EMM',
         "Machine id from http://www.arm.linux.org.uk/developer/machines/")
     atags_addr = Param.Addr("Address where default atags structure should " \
                                 "be written")