Moved LPC specific code from toolchain_makefile into LPC target, added FROM_BEREMIZ variable to tell LPC's makefile it is invoked from here.
<xsd:element name="Rtai">
<xsd:complexType>
%(toolchain_gcc)s
<xsd:attribute name="rtai_config" type="xsd:string" use="optional" default="/usr/realtime/"/>
</xsd:complexType>
</xsd:element>