arm64: struct debug_info: Check CONFIG_HAVE_HW_BREAKPOINT

Check if CONFIG_HAVE_HW_BREAKPOINT is enabled before compiling in extra
data required for hardware breakpoints. Compiling out this code when hw
breakpoints are disabled saves about 272 bytes per struct task_struct.
Signed-off-by: Chris Redmon <credmonster@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/processor.h

@@ -50,6 +50,7 @@ extern phys_addr_t arm64_dma_phys_limit;
 #define ARCH_LOW_ADDRESS_LIMIT	(arm64_dma_phys_limit - 1)
 
 struct debug_info {
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
 	/* Have we suspended stepping by a debugger? */
 	int			suspended_step;
 	/* Allow breakpoints and watchpoints to be disabled for this thread. */
@@ -58,6 +59,7 @@ struct debug_info {
 	/* Hardware breakpoints pinned to this task. */
 	struct perf_event	*hbp_break[ARM_MAX_BRP];
 	struct perf_event	*hbp_watch[ARM_MAX_WRP];
+#endif
 };
 
 struct cpu_context {