ARM: tegra: replace per-device config headers with generic Tegra

Most device headers contain SoC specific part and common Tegra post part.
Add a generic header which can be used by any Tegra device of one of the
supported SoC generations (T20, T30, T114, T124 or T210) without need in
device specific configuration.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/board/avionic-design/tec/Kconfig b/board/avionic-design/tec/Kconfig
index 56b4179..12cc4e1 100644
--- a/board/avionic-design/tec/Kconfig
+++ b/board/avionic-design/tec/Kconfig
@@ -7,7 +7,7 @@
 	default "avionic-design"
 
 config SYS_CONFIG_NAME
-	default "tec"
+	default "tegra"
 
 config TEGRA_BOARD_STRING
 	string "Default Tegra board name"