KVM: ARM: Initial skeleton to compile KVM support

Targets KVM support for Cortex A-15 processors.

Contains all the framework components, make files, header files, some
tracing functionality, and basic user space API.

Only supported core is Cortex-A15 for now.

Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 67874b8..e0627cd 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2322,3 +2322,5 @@
 source "crypto/Kconfig"
 
 source "lib/Kconfig"
+
+source "arch/arm/kvm/Kconfig"