malta: add harddisk support

works with:
qemu-system-mipsel -M malta \
-hda openwrt-malta-le-root.ext4 \
-kernel openwrt-malta-le-vmlinux.elf \
-nographic -append "root=/dev/sda console=ttyS0"

Signed-off-by: Dirk Neukirchen <dirkneukirchen@web.de>

SVN-Revision: 46269

target/linux/malta/config-3.18

@@ -7,6 +7,8 @@ CONFIG_ARCH_MIGHT_HAVE_PC_PARPORT=y
 CONFIG_ARCH_MIGHT_HAVE_PC_SERIO=y
 CONFIG_ARCH_WANT_IPC_PARSE_VERSION=y
 # CONFIG_AX88796_93CX6 is not set
+CONFIG_ATA=y
+CONFIG_ATA_PIIX=y
 CONFIG_BLK_DEV_BSG=y
 CONFIG_BLK_DEV_BSGLIB=y
 # CONFIG_BLK_DEV_DM is not set
@@ -15,6 +17,7 @@ CONFIG_BLK_DEV_BSGLIB=y
 CONFIG_BLK_DEV_RAM=y
 CONFIG_BLK_DEV_RAM_COUNT=16
 CONFIG_BLK_DEV_RAM_SIZE=4096
+CONFIG_BLK_DEV_SD=y
 CONFIG_BOARD_SCACHE=y
 CONFIG_BOOT_ELF32=y
 CONFIG_BOUNCE=y
@@ -52,6 +55,7 @@ CONFIG_DNOTIFY=y
 CONFIG_DUMMY_CONSOLE=y
 CONFIG_EARLY_PRINTK=y
 CONFIG_ENABLE_MUST_CHECK=y
+CONFIG_EXT4_FS=y
 CONFIG_FIRMWARE_IN_KERNEL=y
 CONFIG_FS_POSIX_ACL=y
 CONFIG_GENERIC_ATOMIC64=y