arm64: remove bogus TASK_SIZE_64 check

The comparison between TASK_SIZE_64 and MODULES_VADDR does not
make any sense on arm64, it is simply something that has been
carried over from the ARM port which arm64 is based on. So drop it.
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/memory.h

@@ -70,10 +70,6 @@
 
 #define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
 
-#if TASK_SIZE_64 > MODULES_VADDR
-#error Top of 64-bit user space clashes with start of module space
-#endif
-
 /*
  * Physical vs virtual RAM address space conversion.  These are
  * private definitions which should NOT be used outside memory.h