Convert CONFIG_CMD_PCA953X to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_PCA953X

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/xilinx_zynqmp_zcu102_revB_defconfig b/configs/xilinx_zynqmp_zcu102_revB_defconfig
index 6de052b..7ed0116 100644
--- a/configs/xilinx_zynqmp_zcu102_revB_defconfig
+++ b/configs/xilinx_zynqmp_zcu102_revB_defconfig
@@ -45,6 +45,7 @@
 CONFIG_FPGA_XILINX=y
 CONFIG_FPGA_ZYNQMPPL=y
 CONFIG_DM_GPIO=y
+CONFIG_CMD_PCA953X=y
 CONFIG_DM_MMC=y
 CONFIG_MMC_SDHCI=y
 CONFIG_MMC_SDHCI_ZYNQ=y