tegra2: Add arch_cpu_init() to fire up Cortex-A9

We want to move away from a special Tegra2 start-up, and just use
arch_cpu_init() instead. However, if we run board_init_f() from boot
we need to build it for ARMv4T, since the Tegra's AVP start-up CPU
does not support ARMv7.

The effect of this is to do the AVP init earlier, and in
arch_cpu_init(), rather that board_early_init_f().

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

board/nvidia/common/board.c

@@ -125,9 +125,6 @@ int board_early_init_f(void)
 
 	/* Initialize periph GPIOs */
 	gpio_config_uart();
-
-	/* Init UART, scratch regs, and start CPU */
-	tegra2_start();
 	return 0;
 }
 #endif	/* EARLY_INIT */

board/nvidia/common/board.h

@@ -24,7 +24,6 @@
 #ifndef _BOARD_H_
 #define _BOARD_H_
 
-void tegra2_start(void);
 void gpio_config_uart(void);
 int tegra2_mmc_init(int dev_index, int bus_width, int pwr_gpio, int cd_gpio);