Convert CONFIG_SF_DEFAULT_* to Kconfig

This converts the following to Kconfig:
  CONFIG_SF_DEFAULT_BUS
  CONFIG_SF_DEFAULT_CS
  CONFIG_SF_DEFAULT_MODE
  CONFIG_SF_DEFAULT_SPEED

I use moveconfig script and then manual check on generated u-boot.cfg
to solve the remaining issue.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/configs/controlcenterdc_defconfig b/configs/controlcenterdc_defconfig
index b4b5732..b2b61b2 100644
--- a/configs/controlcenterdc_defconfig
+++ b/configs/controlcenterdc_defconfig
@@ -55,6 +55,7 @@
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_MV=y
 CONFIG_SPI_FLASH=y
+CONFIG_SF_DEFAULT_BUS=1
 CONFIG_SPI_FLASH_STMICRO=y
 CONFIG_PHY_MARVELL=y
 CONFIG_PHY_GIGE=y