Convert CONFIG_ZYNQMP_PSU_INIT_ENABLED to Kconfig

This converts the following to Kconfig:
   CONFIG_ZYNQMP_PSU_INIT_ENABLED

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/xilinx_zynqmp_mini_qspi_defconfig b/configs/xilinx_zynqmp_mini_qspi_defconfig
index 8d7c704..78c9d29 100644
--- a/configs/xilinx_zynqmp_mini_qspi_defconfig
+++ b/configs/xilinx_zynqmp_mini_qspi_defconfig
@@ -10,6 +10,7 @@
 CONFIG_SPL=y
 CONFIG_SYS_MEM_RSVD_FOR_MMU=y
 CONFIG_ZYNQMP_NO_DDR=y
+CONFIG_ZYNQMP_PSU_INIT_ENABLED=y
 # CONFIG_CMD_ZYNQMP is not set
 # CONFIG_PSCI_RESET is not set
 # CONFIG_EXPERT is not set