Fix references to the no-longer-existent misc/ directory in comments, README files, and documentation

configs/lpc4357-evb/Kconfig

@@ -1,6 +1,6 @@
 #
 # For a description of the syntax of this configuration file,
-# see misc/tools/kconfig-language.txt.
+# see the file kconfig-language.txt in the NuttX tools repository.
 #
 
 if ARCH_BOARD_LPC4357_EVB

configs/lpc4357-evb/README.txt

@@ -925,7 +925,7 @@ Where <subdir> is one of the following:
        change this configurations using that tool, you should:
 
        a. Build and install the kconfig-mconf tool.  See nuttx/README.txt
-          and misc/tools/
+          see additional README.txt files in the NuttX tools repository.
 
        b. Execute 'make menuconfig' in nuttx/ in order to start the
           reconfiguration process.

configs/lpc4357-evb/nsh/setenv.sh

@@ -73,7 +73,7 @@ export SCRIPT_BIN="/cygdrive/c/nxp/LPCXpresso_4.2.3_292/lpcxpresso/bin"
 
 # This is the Cygwin path to the location where I build the buildroot
 # toolchain.
-#export TOOLCHAIN_BIN="${WD}/../misc/buildroot/build_arm_nofpu/staging_dir/bin"
+#export TOOLCHAIN_BIN="${WD}/../buildroot/build_arm_nofpu/staging_dir/bin"
 #export SCRIPT_BIN=
 
 # And add the selected toolchain path[s] to the PATH variable