multiarch: introduced the multiarch support into the build system.

* The linker script pie/pie.lds.S is generated from the template
  pie/pie.lds.S.in by prepending the output architecture specification.
  The output architecture is defined by the variable LDARCH.

* Blobs are generated by objcopy instead of ld because the ARM linker
  fails to produce a binary when supplied a script.
  (See http://lists.gnu.org/archive/html/bug-binutils/2008-10/msg00091.html

).

Signed-off-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>