configs: fu540: enable gpio driver

Enable the DM based GPIO driver for FU540-C000 SoC.

Signed-off-by: Sagar Shrikant Kadam <sagar.kadam@sifive.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/board/sifive/fu540/Kconfig b/board/sifive/fu540/Kconfig
index 5d65080..5ca2147 100644
--- a/board/sifive/fu540/Kconfig
+++ b/board/sifive/fu540/Kconfig
@@ -44,6 +44,9 @@
 	imply MMC_SPI
 	imply MMC_BROKEN_CD
 	imply CMD_MMC
+	imply DM_GPIO
+	imply SIFIVE_GPIO
+	imply CMD_GPIO
 	imply SMP
 
 endif