exynos5-dt-types: add board detection for Odroid XU3/XU3L/XU4.

This commit adds additional file with implementation of board
detection code for Odroid-XU3/XU4.

The detection depends on compatible found in fdt:
- "samsung,exynos5" - uses Exynos5 generic code
- "samsung,odroidxu3" - try detect XU3 revision

There are few revisions of Odroid XU3/XU4, each can be detected
by checking the value of channel 9 of built-in ADC:
 Rev   ADC  Board
 0.1     0  XU3 0.1
 0.2   372  XU3 0.2 | XU3L - no DISPLAYPORT
 0.3  1280  XU4 0.1

The detection code depends on the ADC+10% value.

Implementation of functions:
- set_board_type()     - read ADC and set type
- get_board_rev()      - returns board revision: 1..3
- get_board_type()     - returns board type string

Additional functions with return values of bool:
- board_is_generic()   - true if found compatible "samsung,exynos5"
                         but not "samsung,odroidxu3"
- board_is_odroidxu3() - true if found compatible "samsung,odroidxu3"
                         and one of XU3 revision.
- board_is_odroidxu4() - true if found compatible "samsung,odroidxu3"
                         and XU4 revision.

After I2C controller init, the get_board_type() can check
if the XU3 board is a "Lite" variant, by probing chip
0x40 on I2C0 (INA231 - exists only on non-lite).
This is useful for setting fdt file name at misc_init_r().

Enabled configs:
- CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG
- CONFIG_ODROID_REV_AIN
- CONFIG_REVISION_TAG
- CONFIG_BOARD_TYPES

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Cc: Simon Glass <sjg@chromium.org>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/board/samsung/common/exynos5-dt.c b/board/samsung/common/exynos5-dt.c
index 4250f72..4d9e151 100644
--- a/board/samsung/common/exynos5-dt.c
+++ b/board/samsung/common/exynos5-dt.c
@@ -27,7 +27,10 @@
 #include <power/pmic.h>
 #include <power/max77686_pmic.h>
 #include <power/regulator.h>
+#include <power/s2mps11.h>
 #include <power/s5m8767.h>
+#include <samsung/exynos5-dt-types.h>
+#include <samsung/misc.h>
 #include <tmu.h>
 
 DECLARE_GLOBAL_DATA_PTR;
@@ -335,15 +338,24 @@
 #ifdef CONFIG_SET_DFU_ALT_INFO
 char *get_dfu_alt_system(char *interface, char *devstr)
 {
+	char *info = "Not supported!";
+
+	if (board_is_odroidxu4())
+		return info;
+
 	return getenv("dfu_alt_system");
 }
 
 char *get_dfu_alt_boot(char *interface, char *devstr)
 {
+	char *info = "Not supported!";
 	struct mmc *mmc;
 	char *alt_boot;
 	int dev_num;
 
+	if (board_is_odroidxu4())
+		return info;
+
 	dev_num = simple_strtoul(devstr, NULL, 10);
 
 	mmc = find_mmc_device(dev_num);