sunxi: Add missing boot_media fields in the SPL header

Commit b19236fd ("sunxi: Increase SPL header size to 64 bytes to avoid
code corruption") Added defines for MMC0 and SPI as boot identification.
After verifying on an OLinuXino Lime2 with NAND and eMMC, the expected
values have been confirmed and added to spl.h
Signed-off-by: NOlliver Schinagl <oliver@schinagl.nl>
Reviewed-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>

arch/arm/include/asm/arch-sunxi/spl.h

@@ -20,6 +20,8 @@
 
 /* The low 8-bits of the 'boot_media' field in the SPL header */
 #define SUNXI_BOOTED_FROM_MMC0	0
+#define SUNXI_BOOTED_FROM_NAND	1
+#define SUNXI_BOOTED_FROM_MMC2	2
 #define SUNXI_BOOTED_FROM_SPI	3
 
 /* boot head definition from sun4i boot code */