Convert CONFIG_CMD_PCI to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_PCI

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/configs/zc5202_defconfig b/configs/zc5202_defconfig
index d61ed77..6e37265 100644
--- a/configs/zc5202_defconfig
+++ b/configs/zc5202_defconfig
@@ -23,6 +23,7 @@
 CONFIG_CMD_SF=y
 CONFIG_CMD_I2C=y
 CONFIG_CMD_GPIO=y
+CONFIG_CMD_PCI=y
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_SPI_FLASH=y