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/MPC8548CDS_defconfig b/configs/MPC8548CDS_defconfig
index 5c83e80..b6ebac3 100644
--- a/configs/MPC8548CDS_defconfig
+++ b/configs/MPC8548CDS_defconfig
@@ -67,6 +67,7 @@
 # CONFIG_MMC is not set
 CONFIG_MTD_NOR_FLASH=y
 CONFIG_FLASH_CFI_DRIVER=y
+CONFIG_FLASH_SHOW_PROGRESS=0
 CONFIG_SYS_FLASH_EMPTY_INFO=y
 CONFIG_SYS_FLASH_CFI=y
 CONFIG_SYS_MAX_FLASH_SECT=128