Revert "staging: board: Remove macro board_staging"

This reverts commit 850c35bb28ecd80bdbecc5cc4d47d0c6941d6d83 as it
breaks the build.

Cc: Song Chen <[e-mail]>
Reported-by: Stephen Rothwell <[e-mail]>
Cc: Geert Uytterhoeven <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/board/armadillo800eva.c

···
 
 static void __init armadillo800eva_init(void)
 {
-	if (of_machine_is_compatible("renesas,armadillo800eva")) {
-		board_staging_gic_setup_xlate("arm,pl390", 32);
-		board_staging_register_devices(armadillo800eva_devices,
-					       ARRAY_SIZE(armadillo800eva_devices));
-	}
+	board_staging_gic_setup_xlate("arm,pl390", 32);
+	board_staging_register_devices(armadillo800eva_devices,
+				       ARRAY_SIZE(armadillo800eva_devices));
 }
 
-device_initcall(armadillo800eva_init);
+board_staging("renesas,armadillo800eva", armadillo800eva_init);

drivers/staging/board/board.h

···
 void board_staging_register_devices(const struct board_staging_dev *devs,
 				    unsigned int ndevs);
 
+#define board_staging(str, fn)			\
+static int __init runtime_board_check(void)	\
+{						\
+	if (of_machine_is_compatible(str))	\
+		fn();				\
+						\
+	return 0;				\
+}						\
+						\
+device_initcall(runtime_board_check)
+
 #endif /* __BOARD_H__ */

drivers/staging/board/kzm9d.c

···
 
 static void __init kzm9d_init(void)
 {
-	if (of_machine_is_compatible("renesas,kzm9d")) {
-		board_staging_gic_setup_xlate("arm,pl390", 32);
+	board_staging_gic_setup_xlate("arm,pl390", 32);
 
-		if (!board_staging_dt_node_available(usbs1_res,
-						     ARRAY_SIZE(usbs1_res))) {
-			board_staging_gic_fixup_resources(usbs1_res,
-							  ARRAY_SIZE(usbs1_res));
-			platform_device_register_simple("emxx_udc", -1, usbs1_res,
-							ARRAY_SIZE(usbs1_res));
-		}
+	if (!board_staging_dt_node_available(usbs1_res,
+					     ARRAY_SIZE(usbs1_res))) {
+		board_staging_gic_fixup_resources(usbs1_res,
+						  ARRAY_SIZE(usbs1_res));
+		platform_device_register_simple("emxx_udc", -1, usbs1_res,
+						ARRAY_SIZE(usbs1_res));
 	}
 }
 
-device_initcall(kzm9d_init);
+board_staging("renesas,kzm9d", kzm9d_init);