board: sl28: enable EFI_SET_TIME support

Allow EFI to actually set the time before ExitBootServices().

Signed-off-by: Michael Walle <michael@walle.cc>
Reviewed-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/configs/kontron_sl28_defconfig b/configs/kontron_sl28_defconfig
index 90e595f..f24051a 100644
--- a/configs/kontron_sl28_defconfig
+++ b/configs/kontron_sl28_defconfig
@@ -94,3 +94,4 @@
 CONFIG_USB_XHCI_DWC3=y
 CONFIG_OF_LIBFDT_ASSUME_MASK=0x0
 CONFIG_OF_LIBFDT_OVERLAY=y
+CONFIG_EFI_SET_TIME=y