remoteproc: qcom: q6v5-mss: Support loading non-split images

In some software releases the firmware images are not split up with each
loadable segment in it's own file. Check the size of the loaded firmware
to see if it still contains each segment to be loaded, before falling
back to the split-out segments.

Reviewed-by: Jeffrey Hugo <jeffrey.l.hugo@gmail.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>