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/am3517_evm_defconfig b/configs/am3517_evm_defconfig
index 6a38f98..b9edf0d 100644
--- a/configs/am3517_evm_defconfig
+++ b/configs/am3517_evm_defconfig
@@ -4,6 +4,7 @@
 CONFIG_SPL=y
 CONFIG_FIT=y
 CONFIG_SYS_EXTRA_OPTIONS="NAND"
+CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="AM3517_EVM # "
 # CONFIG_CMD_IMI is not set
 # CONFIG_CMD_IMLS is not set