arm: at91: use macro to declare soc boot data

Instead of check the pointer of the init function, check the new builtin bool
to known if the soc is enabled.

This is needed as with the switch to the pinctrl the init will be NULL on pure
DT SoC.

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/arch/arm/mach-at91/at91sam9rl.c b/arch/arm/mach-at91/at91sam9rl.c
index 72e9084..cbe72e4 100644
--- a/arch/arm/mach-at91/at91sam9rl.c
+++ b/arch/arm/mach-at91/at91sam9rl.c
@@ -338,10 +338,10 @@
 	0,	/* Advanced Interrupt Controller */
 };
 
-struct at91_init_soc __initdata at91sam9rl_soc = {
+AT91_SOC_START(sam9rl)
 	.map_io = at91sam9rl_map_io,
 	.default_irq_priority = at91sam9rl_default_irq_priority,
 	.ioremap_registers = at91sam9rl_ioremap_registers,
 	.register_clocks = at91sam9rl_register_clocks,
 	.init = at91sam9rl_initialize,
-};
+AT91_SOC_END