mtd: mchp23k256: use SPI match data for chip caps

In the Linux kernel, the following vulnerability has been resolved: mtd: mchp23k256: use SPI match data for chip caps The driver stores chip capacity information in both the OF match table and the SPI id table. Probe currently uses of_device_get_match_data(), so a non-OF SPI modalias match falls back to mchp23k256_caps even when the SPI id table selected a different part. Use spi_get_device_match_data() so SPI id-table driver_data is consumed when OF match data is absent. This keeps the existing default fallback while avoiding the wrong MTD geometry for id-table-only matches.