cmd: Kconfig: migrate CONFIG_SYS_PROMPT_HUSH_PS2

Move CONFIG_SYS_PROMPT_HUSH_PS2 in Kconfig, depending
on CONFIG_HUSH_PARSER, and remove the default value defined
in cli_hush.c under __U_BOOT__.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/README b/README
index 7b73a1c..5ca11f2 100644
--- a/README
+++ b/README
@@ -1925,13 +1925,6 @@
 		try longer timeout such as
 		#define CONFIG_NFS_TIMEOUT 10000UL
 
-- Command Interpreter:
-		CONFIG_SYS_PROMPT_HUSH_PS2
-
-		This defines the secondary prompt string, which is
-		printed when the command interpreter needs more input
-		to complete a command. Usually "> ".
-
 	Note:
 
 		In the current implementation, the local variables
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 1595de9..98cf543 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -55,6 +55,15 @@
 	  This string is displayed in the command line to the left of the
 	  cursor.
 
+config SYS_PROMPT_HUSH_PS2
+	string "Hush shell secondary prompt"
+	depends on HUSH_PARSER
+	default "> "
+	help
+	  This defines the secondary prompt string, which is
+	  printed when the command interpreter needs more input
+	  to complete a command. Usually "> ".
+
 config SYS_XTRACE
 	string "Command execution tracer"
 	depends on CMDLINE
diff --git a/common/cli_hush.c b/common/cli_hush.c
index 66995c2..b7f0f0f 100644
--- a/common/cli_hush.c
+++ b/common/cli_hush.c
@@ -84,9 +84,6 @@
 #include <cli.h>
 #include <cli_hush.h>
 #include <command.h>        /* find_cmd */
-#ifndef CONFIG_SYS_PROMPT_HUSH_PS2
-#define CONFIG_SYS_PROMPT_HUSH_PS2	"> "
-#endif
 #endif
 #ifndef __U_BOOT__
 #include <ctype.h>     /* isalpha, isdigit */
diff --git a/scripts/config_whitelist.txt b/scripts/config_whitelist.txt
index 8b4fcba..31acc36 100644
--- a/scripts/config_whitelist.txt
+++ b/scripts/config_whitelist.txt
@@ -3508,7 +3508,6 @@
 CONFIG_SYS_POST_WORD_ADDR
 CONFIG_SYS_PPC_DDR_WIMGE
 CONFIG_SYS_PQSPAR
-CONFIG_SYS_PROMPT_HUSH_PS2
 CONFIG_SYS_PSDPAR
 CONFIG_SYS_PSSR_VAL
 CONFIG_SYS_PTCPAR