SPL: add support to boot from a partition type

the socfpga bootrom supports mmc booting from either a raw image
starting at 0x0, or from a partition of type 0xa2.  This patch
adds support for locating the boot image in the first type 0xa2
partition found.

Assigned a partition number of -1 will cause a search for a
partition of type CONFIG_SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION_TYPE
and use it to find the u-boot image

Signed-off-by: Dalon Westergreen <dwesterg@gmail.com>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index cf714c2..baff7b6 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -96,6 +96,22 @@
 	  Address on the MMC to load U-Boot from, when the MMC is being used
 	  in raw mode. Units: MMC sectors (1 sector = 512 bytes).
 
+config SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION_TYPE
+	bool "MMC raw mode: by partition type"
+	depends on SPL && DOS_PARTITION && \
+		SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION
+	help
+	  Use partition type for specifying U-Boot partition on MMC/SD in
+	  raw mode. U-Boot will be loaded from the first partition of this
+	  type to be found.
+
+config SYS_MMCSD_RAW_MODE_U_BOOT_PARTITION_TYPE
+	hex "Partition Type on the MMC to load U-Boot from"
+	depends on SPL && SYS_MMCSD_RAW_MODE_U_BOOT_USE_PARTITION_TYPE
+	help
+	  Partition Type on the MMC to load U-Boot from, when the MMC is being
+	  used in raw mode.
+
 config TPL
 	bool
 	depends on SPL && SUPPORT_TPL