NVMEM consumer driver APIs

NVMEM consumers are drivers who access the storage exposed by the producer. These drivers can pull the NVMEM consumer API by including <linux/nvmem-consumer.h>, which will bring the following cell-based APIs in:

struct nvmem_cell *nvmem_cell_get(struct device *dev,
                                  const char *name);
struct nvmem_cell *devm_nvmem_cell_get(struct device *dev,
                                       const char *name);
void nvmem_cell_put(struct nvmem_cell *cell);
void devm_nvmem_cell_put(struct device *dev,
           &...