Tegra: Change Tegra20 to Tegra in common code, prep for T30

Convert TEGRA20_ defines to either TEGRA_ or NV_PA_ where appropriate.
Convert tegra20_ source file and function names to tegra_, also.

Upcoming Tegra30 port will use common code/defines/names where possible.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
diff --git a/drivers/input/Makefile b/drivers/input/Makefile
index 68c6a16..0805e86 100644
--- a/drivers/input/Makefile
+++ b/drivers/input/Makefile
@@ -26,7 +26,7 @@
 LIB	:= $(obj)libinput.o
 
 COBJS-$(CONFIG_I8042_KBD) += i8042.o
-COBJS-$(CONFIG_TEGRA20_KEYBOARD) += tegra-kbc.o
+COBJS-$(CONFIG_TEGRA_KEYBOARD) += tegra-kbc.o
 ifdef CONFIG_PS2KBD
 COBJS-y += keyboard.o pc_keyb.o
 COBJS-$(CONFIG_PS2MULT) += ps2mult.o ps2ser.o