avr32: factor out cpu_mmc_init()

cpu_mmc_init() is required by the init sequence to have a working MMC interface
on avr32. This will not be included in the binary if we omit the avr32 board.c
when building the generic board.

Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/arch/avr32/cpu/Makefile b/arch/avr32/cpu/Makefile
index 00cede3..e111db3 100644
--- a/arch/avr32/cpu/Makefile
+++ b/arch/avr32/cpu/Makefile
@@ -16,5 +16,6 @@
 obj-y			+= interrupts.o
 obj-$(CONFIG_PORTMUX_PIO) += portmux-pio.o
 obj-$(CONFIG_PORTMUX_GPIO) += portmux-gpio.o
+obj-y += mmc.o
 
 obj-$(if $(filter at32ap700x,$(SOC)),y) += at32ap700x/
diff --git a/arch/avr32/cpu/mmc.c b/arch/avr32/cpu/mmc.c
new file mode 100644
index 0000000..b7213e4
--- /dev/null
+++ b/arch/avr32/cpu/mmc.c
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2004-2006 Atmel Corporation
+ * Copyright (C) 2015 Andreas Bießmann <andreas.devel@googlmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+#include <common.h>
+#include <atmel_mci.h>
+#include <asm/arch/hardware.h>
+
+/* provide cpu_mmc_init, to overwrite provide board_mmc_init */
+int cpu_mmc_init(bd_t *bd)
+{
+	/* This calls the atmel_mci_init in gen_atmel_mci.c */
+	return atmel_mci_init((void *)ATMEL_BASE_MMCI);
+}
diff --git a/arch/avr32/lib/board.c b/arch/avr32/lib/board.c
index 95f9526..e86530f 100644
--- a/arch/avr32/lib/board.c
+++ b/arch/avr32/lib/board.c
@@ -9,7 +9,6 @@
 #include <stdio_dev.h>
 #include <version.h>
 #include <net.h>
-#include <atmel_mci.h>
 
 #ifdef CONFIG_BITBANGMII
 #include <miiphy.h>
@@ -38,13 +37,6 @@
 int board_postclk_init(void) __attribute__((weak, alias("__do_nothing")));
 int board_early_init_r(void) __attribute__((weak, alias("__do_nothing")));
 
-/* provide cpu_mmc_init, to overwrite provide board_mmc_init */
-int cpu_mmc_init(bd_t *bd)
-{
-	/* This calls the atmel_mci_init in gen_atmel_mci.c */
-	return atmel_mci_init((void *)ATMEL_BASE_MMCI);
-}
-
 static int init_baudrate(void)
 {
 	gd->baudrate = getenv_ulong("baudrate", 10, CONFIG_BAUDRATE);