Tegra: platform: support Tegra186 chip id

This patch adds support to read the chip id and identify if
the current platform is Tegra186.
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_platform.c

@@ -69,6 +69,7 @@ typedef enum tegra_platform {
 typedef enum tegra_chipid {
 	TEGRA_CHIPID_TEGRA13 = 0x13,
 	TEGRA_CHIPID_TEGRA21 = 0x21,
+	TEGRA_CHIPID_TEGRA18 = 0x18,
 } tegra_chipid_t;
 
 /*
@@ -109,6 +110,13 @@ uint8_t tegra_chipid_is_t210(void)
 	return (chip_id == TEGRA_CHIPID_TEGRA21);
 }
 
+uint8_t tegra_chipid_is_t186(void)
+{
+	uint32_t chip_id = (tegra_get_chipid() >> CHIP_ID_SHIFT) & CHIP_ID_MASK;
+
+	return (chip_id == TEGRA_CHIPID_TEGRA18);
+}
+
 /*
  * Read the chip ID value and derive the platform
  */

plat/nvidia/tegra/include/tegra_platform.h

@@ -42,8 +42,10 @@ uint32_t tegra_get_chipid_minor(void);
 /*
  * Tegra chip identifiers
  */
-uint8_t tegra_is_t132(void);
-uint8_t tegra_is_t210(void);
+uint8_t tegra_chipid_is_t132(void);
+uint8_t tegra_chipid_is_t210(void);
+uint8_t tegra_chipid_is_t186(void);
+
 
 /*
  * Tegra platform identifiers