x86: add RESERVE_BRK_ARRAY() helper

Useful when converting static arrays into boottime brk allocated objects.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>

arch/x86/include/asm/setup.h

@@ -93,6 +93,11 @@ void *extend_brk(size_t size, size_t align);
 			: : "i" (sz));					\
 	}
 
+/* Helper for reserving space for arrays of things */
+#define RESERVE_BRK_ARRAY(type, name, entries)		\
+	type *name;					\
+	RESERVE_BRK(name, sizeof(type) * entries)
+
 #ifdef __i386__
 
 void __init i386_start_kernel(void);