[PATCH] pcdp.c build fix

In file included from drivers/firmware/pcdp.c:18:
drivers/firmware/pcdp.h:48: error: field `addr' has incomplete type
drivers/firmware/pcdp.c: In function `setup_serial_console':
drivers/firmware/pcdp.c:27: error:  `ACPI_ADR_SPACE_SYSTEM_MEMORY' undeclared (first use in this  function)

Cc: <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>