microblaze: spl: add board_boot_order() implementation

Microblaze has three boot modes defined in microblaze/include/asm/spl.h,
but only booting from NOR flash is currently useable. Add a custom
board_boot_order() implementation so that RAM and SPI boot modes can also
be selected if the corresponding load-image support is present.

Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Link: https://lore.kernel.org/r/20211130163358.2531677-3-ovidiu.panait@windriver.com
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/microblaze/cpu/spl.c b/arch/microblaze/cpu/spl.c
index 86522f8..06d4af9 100644
--- a/arch/microblaze/cpu/spl.c
+++ b/arch/microblaze/cpu/spl.c
@@ -15,9 +15,11 @@
 
 bool boot_linux;
 
-u32 spl_boot_device(void)
+void board_boot_order(u32 *spl_boot_list)
 {
-	return BOOT_DEVICE_NOR;
+	spl_boot_list[0] = BOOT_DEVICE_NOR;
+	spl_boot_list[1] = BOOT_DEVICE_RAM;
+	spl_boot_list[2] = BOOT_DEVICE_SPI;
 }
 
 /* Board initialization after bss clearance */