arm64: Promote KERNEL_START/KERNEL_END definitions to a header file

KERNEL_START and KERNEL_END are useful outside head.S, move them to a
header file.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
(cherry picked from commit 28c7258330ee4ce701a4da7af96d6605d1a0b3bd)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

Author: James Morse

arch/arm64/include/asm/memory.h

@@ -70,6 +70,9 @@
 
 #define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE / 4))
 
+#define KERNEL_START      _text
+#define KERNEL_END        _end
+
 /*
  * Physical vs virtual RAM address space conversion.  These are
  * private definitions which should NOT be used outside memory.h

arch/arm64/kernel/head.S

@@ -48,9 +48,6 @@
 #error TEXT_OFFSET must be less than 2MB
 #endif
 
-#define KERNEL_START	_text
-#define KERNEL_END	_end
-
 /*
  * Kernel startup entry point.
  * ---------------------------