xilinx: Enable SIMPLE_PM_BUS

Enable simple-pm-bus driver to handle case where axi bus coming between PS
(fixed) part to PL (programmable) part has own clock or power domain.
That's why enable driver to be ready for this configuration.

Signed-off-by: Michal Simek <michal.simek@amd.com>
Link: https://lore.kernel.org/r/b9f4bb85be502616edf3be2b79e52a0e2c03e821.1725349691.git.michal.simek@amd.com
diff --git a/configs/amd_versal2_virt_defconfig b/configs/amd_versal2_virt_defconfig
index c4bf771..78f6ffc 100644
--- a/configs/amd_versal2_virt_defconfig
+++ b/configs/amd_versal2_virt_defconfig
@@ -72,6 +72,7 @@
 CONFIG_IP_DEFRAG=y
 CONFIG_SYS_FAULT_ECHO_LINK_DOWN=y
 CONFIG_TFTP_BLOCKSIZE=4096
+CONFIG_SIMPLE_PM_BUS=y
 CONFIG_CLK_CCF=y
 CONFIG_CLK_SCMI=y
 CONFIG_DFU_RAM=y