ArmPkg/ArmMmuLib: Drop buggy secure memory type check

Jake reports that the IS_ARM_MEMORY_REGION_ATTRIBUTES_SECURE() macro is
no longer accurate since commit 852227a9d5 ("ArmPkg/Mmu: Remove
handling of NONSECURE memory regions").

Fortunately, it only affects the NS bit in level 1 short descriptors,
which is ignored when executing in non-secure mode. And given that
running UEFI in the secure world is not a use case we aim to support,
let's just drop this logic altogether.

Reported-by: Jake Garver <jake@nvidia.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Leif Lindholm <quic_llindhol@quicinc.com>

ArmPkg/Include/Library/ArmLib.h

@@ -45,8 +45,6 @@ typedef enum {
   ARM_MEMORY_REGION_ATTRIBUTE_DEVICE,
 } ARM_MEMORY_REGION_ATTRIBUTES;
 
-#define IS_ARM_MEMORY_REGION_ATTRIBUTES_SECURE(attr)  ((UINT32)(attr) & 1)
-
 typedef struct {
   EFI_PHYSICAL_ADDRESS            PhysicalBase;
   EFI_VIRTUAL_ADDRESS             VirtualBase;