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/novena_defconfig b/configs/novena_defconfig
index 9ffffe0..a75e27d 100644
--- a/configs/novena_defconfig
+++ b/configs/novena_defconfig
@@ -30,6 +30,7 @@
 CONFIG_CMD_USB=y
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_SATA=y
+CONFIG_CMD_PCI=y
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_TIME=y
 CONFIG_CMD_EXT4_WRITE=y