SMM: Add option for SPI driver to be available in SMM

- add Kconfig option for CONFIG_SPI_FLASH_SMM
- compile subsystem and chip drivers for smm if enabled
- change mdelay(1) to udelay(500) since mdelay is not defined
  in SMM and a 1ms delay is worth avoiding
- make flash chip structure non-const so the probe function
  pointers can be relocated for use in TSEG
- Make SMM PCI access possible in southbridge SPI code

Change-Id: Icfcbbe8e4e56658769d46af0b5bf6c79a6432641
Signed-off-by: Duncan Laurie <dlaurie@chromium.org>
Reviewed-on: http://review.coreboot.org/1313
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
5 files changed