Convert CONFIG_FLASH_SHOW_PROGRESS to Kconfig

This converts the following to Kconfig:
   CONFIG_FLASH_SHOW_PROGRESS

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/xilinx_zynq_virt_defconfig b/configs/xilinx_zynq_virt_defconfig
index a4c555d..5068565 100644
--- a/configs/xilinx_zynq_virt_defconfig
+++ b/configs/xilinx_zynq_virt_defconfig
@@ -109,6 +109,7 @@
 CONFIG_MMC_SDHCI_ZYNQ=y
 CONFIG_MTD=y
 CONFIG_MTD_NOR_FLASH=y
+CONFIG_FLASH_SHOW_PROGRESS=10
 CONFIG_CFI_FLASH=y
 CONFIG_SYS_FLASH_USE_BUFFER_WRITE=y
 CONFIG_SYS_FLASH_CFI=y