armv8: Add global variable resv_ram

Use gd->arch.resv_ram to track reserved memory allocation.

Signed-off-by: York Sun <york.sun@nxp.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/include/asm/global_data.h b/arch/arm/include/asm/global_data.h
index aee87cd..dfcbcce 100644
--- a/arch/arm/include/asm/global_data.h
+++ b/arch/arm/include/asm/global_data.h
@@ -59,6 +59,13 @@
 	phys_addr_t secure_ram;
 	unsigned long tlb_allocated;
 #endif
+#ifdef CONFIG_RESV_RAM
+	/*
+	 * Reserved RAM for memory resident, eg. Management Complex (MC)
+	 * driver which continues to run after U-Boot exits.
+	 */
+	phys_addr_t resv_ram;
+#endif
 
 #ifdef CONFIG_ARCH_OMAP2
 	u32 omap_boot_device;