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/devkit3250_defconfig b/configs/devkit3250_defconfig
index 6630069..cd5ddc4 100644
--- a/configs/devkit3250_defconfig
+++ b/configs/devkit3250_defconfig
@@ -65,6 +65,7 @@
 CONFIG_MTD=y
 CONFIG_MTD_NOR_FLASH=y
 CONFIG_FLASH_CFI_DRIVER=y
+CONFIG_FLASH_SHOW_PROGRESS=0
 CONFIG_SYS_FLASH_PROTECTION=y
 CONFIG_SYS_FLASH_CFI=y
 CONFIG_SYS_MAX_FLASH_SECT=71