remoteproc: Rename "load_rsc_table" to "parse_fw"

The resource table is just one possible source of information that can
be extracted from the firmware file. Generalize this interface to allow
drivers to override this with parsers of other types of information.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
(cherry picked from commit c1d35c1a)