WEBOS: Added a default prefix and enforcing docdir, datadir and plugin directory.

configure

@@ -1138,6 +1138,10 @@ webos)
 	_host_os=webos
 	_host_cpu=arm
 	_host_alias=arm-none-linux-gnueabi
+	test "x$prefix" = xNONE && prefix=/media/cryptofs/apps/usr/palm/applications/org.scummvm.scummvm
+	datarootdir='${prefix}/data'
+	datadir='${datarootdir}'
+	docdir='${prefix}/doc'
 	;;
 wii)
 	_host_os=wii
@@ -2928,6 +2932,9 @@ case $_backend in
 		# Add ../plugins as a path so plugins can be found when running from a .PND.
 		DEFINES="$DEFINES -DPLUGIN_DIRECTORY=\\\"../plugins\\\""
 		;;
+	webos)
+		DEFINES="$DEFINES -DPLUGIN_DIRECTORY=\\\"$libdir\\\""
+		;;
 	*)
 		DEFINES="$DEFINES -DPLUGIN_DIRECTORY=\\\"$libdir/scummvm\\\""
 		;;