imx: bootaux: fix stack and pc assignment on 64-bit platforms

Using ulong is wrong as its size depends on the Host CPU architecture
(32-bit vs. 64-bit) although the Cortex-M4 is always 32-bit.

Without this patch, the stack and PC are obviously wrong and it
generates an abort when used on 64-bit processors such as the i.MX8MQ.

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/imx_bootaux.c b/arch/arm/mach-imx/imx_bootaux.c
index a1ea5c1..3103001 100644
--- a/arch/arm/mach-imx/imx_bootaux.c
+++ b/arch/arm/mach-imx/imx_bootaux.c
@@ -17,8 +17,8 @@
 	if (!boot_private_data)
 		return -EINVAL;
 
-	stack = *(ulong *)boot_private_data;
-	pc = *(ulong *)(boot_private_data + 4);
+	stack = *(u32 *)boot_private_data;
+	pc = *(u32 *)(boot_private_data + 4);
 
 	/* Set the stack and pc to M4 bootROM */
 	writel(stack, M4_BOOTROM_BASE_ADDR);