configs: Re-sync HUSH options

Move all cases of CONFIG_SYS_HUSH_PARSER out of the config.h files.  Remove
all cases of CONFIG_SYS_PROMPT_HUSH_PS2 as everyone uses the default.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/mgcoge3un_defconfig b/configs/mgcoge3un_defconfig
index f1e8fd7..5143214 100644
--- a/configs/mgcoge3un_defconfig
+++ b/configs/mgcoge3un_defconfig
@@ -2,6 +2,7 @@
 CONFIG_KIRKWOOD=y
 CONFIG_TARGET_KM_KIRKWOOD=y
 CONFIG_SYS_EXTRA_OPTIONS="KM_MGCOGE3UN"
+CONFIG_HUSH_PARSER=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set
 CONFIG_SPI_FLASH=y