Remove redundant checks in constant_time.c

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/constant_time.c b/library/constant_time.c
index c62ec13..5e1a577 100644
--- a/library/constant_time.c
+++ b/library/constant_time.c
@@ -64,9 +64,7 @@
  */
 #if defined(MBEDTLS_EFFICIENT_UNALIGNED_ACCESS) && defined(MBEDTLS_HAVE_ASM)
 #if ((defined(__arm__) || defined(__thumb__) || defined(__thumb2__)) && \
-    (UINTPTR_MAX == 0xfffffffful)) || \
-    (defined(__aarch64__) && ((UINTPTR_MAX == 0xffffffffull) || \
-    (UINTPTR_MAX == 0xffffffffffffffffull)))
+    (UINTPTR_MAX == 0xfffffffful)) || defined(__aarch64__)
 /* We check pointer sizes to avoid issues with them not matching register size requirements */
 #define MBEDTLS_EFFICIENT_UNALIGNED_VOLATILE_ACCESS
 #endif