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/mx6slevk_spl_defconfig b/configs/mx6slevk_spl_defconfig
index fee352c..995f8d1 100644
--- a/configs/mx6slevk_spl_defconfig
+++ b/configs/mx6slevk_spl_defconfig
@@ -3,6 +3,7 @@
 CONFIG_TARGET_MX6SLEVK=y
 CONFIG_SPL=y
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/imx-common/spl_sd.cfg,SPL,MX6SL"
+CONFIG_HUSH_PARSER=y
 CONFIG_CMD_GPIO=y
 CONFIG_DM=y
 CONFIG_SPI_FLASH=y