bsp: k230: eliminate warnings for kconfig

When run kconfig, see warnings as followings:

Kconfig:5: warning: BSP_ROOT has 'option env="BSP_DIR"',...
Kconfig:10: warning: RTT_ROOT has 'option env="RTT_DIR"',...
Kconfig:15: warning: PKGS_ROOT has 'option env="PKGS_DIR"',...
...
warning: the choice symbol PKG_USING_ZLIB_LATEST_VERSION (...)
is selected by the following symbols, but select/imply has no
effect on choice symbols
 - BSP_ROOTFS_TYPE_CROMFS (defined at Kconfig:41)
warning: the value '0xF00000000' is invalid for C908_PLIC_PHY_ADDR...

Trying to cleanup Kconfig and re-run menuconfig to update.

Signed-off-by: Chen Wang <unicorn_wang@outlook.com>

bsp/k230/.config

@@ -1494,5 +1494,4 @@ CONFIG_PKG_ZLIB_VER="latest"
 
 CONFIG_BOARD_fpgac908=y
 CONFIG___STACKSIZE__=65536
-CONFIG_C908_PLIC_PHY_ADDR=0xF00000000
 CONFIG_BSP_ROOTFS_TYPE_CROMFS=y

bsp/k230/Kconfig

@@ -1,19 +1,10 @@
 mainmenu "RT-Thread Project Configuration"
 
-config BSP_DIR
-    string
-    option env="BSP_ROOT"
-    default "."
+BSP_DIR := .
 
-config RTT_DIR
-    string
-    option env="RTT_ROOT"
-    default "../../"
+RTT_DIR := ../../
 
-config PKGS_DIR
-    string
-    option env="PKGS_ROOT"
-    default "packages"
+PKGS_DIR := packages
 
 source "$RTT_DIR/Kconfig"
 source "$PKGS_DIR/Kconfig"
@@ -34,13 +25,8 @@ config __STACKSIZE__
     int "stack size for interrupt"
     default 4096
 
-config C908_PLIC_PHY_ADDR
-    int "PLIC base address"
-    default 0xF00000000
-
 config BSP_ROOTFS_TYPE_CROMFS
     bool "Use CROMFS as ROOTFS"
     select RT_USING_DFS_CROMFS
     select PKG_USING_ZLIB
-    select PKG_USING_ZLIB_LATEST_VERSION
     default y

bsp/k230/rtconfig.h

@@ -562,7 +562,6 @@
 /* end of Drivers Configuration */
 #define BOARD_fpgac908
 #define __STACKSIZE__ 65536
-#define C908_PLIC_PHY_ADDR 0xF00000000
 #define BSP_ROOTFS_TYPE_CROMFS
 
 #endif