Convert CONFIG_I2C_SET_DEFAULT_BUS_NUM et al to Kconfig

This converts the following to Kconfig:
   CONFIG_I2C_SET_DEFAULT_BUS_NUM
   CONFIG_I2C_DEFAULT_BUS_NUMBER

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/P2041RDB_SPIFLASH_defconfig b/configs/P2041RDB_SPIFLASH_defconfig
index 738b6bca..80fb3e6 100644
--- a/configs/P2041RDB_SPIFLASH_defconfig
+++ b/configs/P2041RDB_SPIFLASH_defconfig
@@ -37,6 +37,7 @@
 CONFIG_DM=y
 CONFIG_FSL_CAAM=y
 CONFIG_DM_I2C=y
+CONFIG_I2C_SET_DEFAULT_BUS_NUM=y
 CONFIG_SYS_I2C_FSL=y
 CONFIG_SYS_I2C_EEPROM_ADDR=0x50
 CONFIG_FSL_ESDHC=y