omap_gpmc: Refactor omap_gpmc_cs_map and omap_gpmc_cs_unmap Refactor the omap_gpmc_cs_map/unmap functions: * take the omap_gpmc_s* and a chipselect id rather than the omap_gpmc_cs_file_s*, so they have access to the general gpmc member fields * extract the base and mask from the config registers in the functions rather than at every callsite * check for CSVALID in the functions rather than at every callsite Signed-off-by: Peter Maydell <peter.maydell@linaro.org>