ODROID-XU4: Switch SPI driver to kernel buildin type

Sometime SPI client driver can not be loaded due to driver loading order.
[    5.218291] fbtft_device:  'fb' Platform devices registered:
[    5.218449] fbtft_device:  spi_busnum_to_master(1) returned NULL
[    5.223074] fbtft_device: failed to register SPI device

Change-Id: I0ffe2e9ab3607548bfe015e622bf4424ed2671a0
Signed-off-by: Dongjin Kim <tobetter@gmail.com>

arch/arm/configs/odroidxu4_defconfig

@@ -1684,7 +1684,7 @@ CONFIG_SPI_MASTER=y
 # CONFIG_SPI_PL022 is not set
 # CONFIG_SPI_PXA2XX_PCI is not set
 # CONFIG_SPI_ROCKCHIP is not set
-CONFIG_SPI_S3C64XX=m
+CONFIG_SPI_S3C64XX=y
 # CONFIG_SPI_SC18IS602 is not set
 # CONFIG_SPI_XCOMM is not set
 # CONFIG_SPI_XILINX is not set