base/firmware retry firmware load after rootfs mount

base/firmware retry firmware load after rootfs mount

Return -EPROBE_DEFER for request_firmware() until root filesystem is
mounted. In case of request_firmware_nowait() create a list of deferred
firmware load requests, and retry firmware load after root filesytem is
mounted.

This allows to have wifi drivers build into the kernel, but
the firmware files shipped on the root filesystem.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Christoph Manszewski <c.manszewski@samsung.com>
Change-Id: I40c0a2a98ca9b1a95fb743a848d2366250cae839