Convert CONFIG_SYS_SPD_BUS_NUM to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_SPD_BUS_NUM

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/P1010RDB-PB_36BIT_SDCARD_defconfig b/configs/P1010RDB-PB_36BIT_SDCARD_defconfig
index 81231e1..e26ffa2 100644
--- a/configs/P1010RDB-PB_36BIT_SDCARD_defconfig
+++ b/configs/P1010RDB-PB_36BIT_SDCARD_defconfig
@@ -70,6 +70,7 @@
 CONFIG_SYS_SATA_MAX_DEVICE=2
 CONFIG_FSL_CAAM=y
 CONFIG_DDR_CLK_FREQ=66666666
+CONFIG_SYS_SPD_BUS_NUM=1
 CONFIG_CHIP_SELECTS_PER_CTRL=1
 CONFIG_SPL_COMMON_INIT_DDR=y
 CONFIG_DM_I2C=y