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/integratorap_cm926ejs_defconfig b/configs/integratorap_cm926ejs_defconfig
index 77aa6a8..4e071d5 100644
--- a/configs/integratorap_cm926ejs_defconfig
+++ b/configs/integratorap_cm926ejs_defconfig
@@ -8,6 +8,7 @@
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="Integrator-AP # "
 CONFIG_CMD_ARMFLASH=y
+CONFIG_CMD_PCI=y
 # CONFIG_CMD_SETEXPR is not set
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y