dm: Remove spi_init() from board_r.c when using driver model

Driver model does its own init, so we don't need this.

There is still a call in board_f.c but it is only enabled by CONFIG_HARD_SPI.
It is easy enough to disable that option when converting boards which use
it to driver model.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>

common/board_r.c

@@ -354,7 +354,7 @@ static int initr_flash(void)
 }
 #endif
 
-#ifdef CONFIG_PPC
+#if defined(CONFIG_PPC) && !defined(CONFIG_DM_SPI)
 static int initr_spi(void)
 {
 	/* PPC does this here */