dm: test: Add test for part_get_info_by_type

Adds a test suite to ensure that part_get_info_by_type works correctly
by creating a hybrid GPT/MBR partition table and reading both.

Signed-off-by: Joshua Watt <JPEWhacker@gmail.com>
[trini: Add this on the other sandbox configs]
Signedd-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index e7657d4..8aa2956 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -44,6 +44,7 @@
 CONFIG_CMD_GPT=y
 CONFIG_CMD_IDE=y
 CONFIG_CMD_I2C=y
+CONFIG_CMD_MBR=y
 CONFIG_CMD_MMC=y
 CONFIG_CMD_OSD=y
 CONFIG_CMD_PCI=y