firmware_class.c

Some low memory systems with complex peripherals cannot
afford to have the relatively large firmware images taking
up valuable memory during suspend and resume. Change the
internal implementation of firmware_class to disallow
caching based on a configurable option. In the near future,
variants of request_firmware will take advantage of this
configurability.

Change-Id: I44be7ce3b308b642fb018086def99fcb800a1109
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>