xilinx: Enable CMD_GREPENV/SETEXPR by default

Enable both of these commands in Xilinx SoCs to be able to use them in boot
scripts.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/1a612be7e09e9bc502f30e1f025441ccf8accba5.1661340513.git.michal.simek@amd.com
diff --git a/configs/microblaze-generic_defconfig b/configs/microblaze-generic_defconfig
index b5c5efe5..01c93d5 100644
--- a/configs/microblaze-generic_defconfig
+++ b/configs/microblaze-generic_defconfig
@@ -43,9 +43,9 @@
 CONFIG_CMD_IMLS=y
 CONFIG_CMD_SPL=y
 CONFIG_CMD_ASKENV=y
+CONFIG_CMD_GREPENV=y
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_SAVES=y
-# CONFIG_CMD_SETEXPR is not set
 CONFIG_BOOTP_BOOTFILESIZE=y
 CONFIG_CMD_TFTPPUT=y
 CONFIG_CMD_CACHE=y