Convert CONFIG_DEFAULT_SPI_* to Kconfig

This converts the following to Kconfig:
   CONFIG_DEFAULT_SPI_BUS
   CONFIG_DEFAULT_SPI_MODE

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/configs/ls1012aqds_tfa_defconfig b/configs/ls1012aqds_tfa_defconfig
index a41757d..d18d40a 100644
--- a/configs/ls1012aqds_tfa_defconfig
+++ b/configs/ls1012aqds_tfa_defconfig
@@ -27,6 +27,8 @@
 CONFIG_CMD_MMC=y
 CONFIG_CMD_PCI=y
 CONFIG_CMD_SF=y
+CONFIG_CMD_SPI=y
+CONFIG_DEFAULT_SPI_BUS=1
 CONFIG_CMD_USB=y
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_CMD_CACHE=y