spi: Migrate CONFIG_SH_QSPI to Kconfig

Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
diff --git a/configs/silk_defconfig b/configs/silk_defconfig
index b01d198..bba0ce7 100644
--- a/configs/silk_defconfig
+++ b/configs/silk_defconfig
@@ -33,6 +33,7 @@
 CONFIG_SH_ETHER=y
 CONFIG_BAUDRATE=38400
 CONFIG_SCIF_CONSOLE=y
+CONFIG_SH_QSPI=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_STORAGE=y