ARM: tegra: prototype pinmux_init() in board.h

pinmux_init() is a board-level function, not a pinmux driver function.
Move the prototype to a board header rather than the driver header.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/board/nvidia/common/board.c b/board/nvidia/common/board.c
index 3b18e28..d3d7bbd 100644
--- a/board/nvidia/common/board.c
+++ b/board/nvidia/common/board.c
@@ -48,6 +48,12 @@
 	CONFIG_TEGRA_BOARD_STRING
 };
 
+void __pinmux_init(void)
+{
+}
+
+void pinmux_init(void) __attribute__((weak, alias("__pinmux_init")));
+
 void __pin_mux_usb(void)
 {
 }
@@ -176,9 +182,7 @@
 
 int board_early_init_f(void)
 {
-#if !defined(CONFIG_TEGRA20)
 	pinmux_init();
-#endif
 	board_init_uart_f();
 
 	/* Initialize periph GPIOs */