bugfix(psram): improve spi cs timing settings for psram

bugfix(psram): improve spi cs timing settings for psram

1. remove redundant SPI clock settings, use rom functions to set clock.
2. remove redundant SPI cs setup and hold settings.
3. for old 32Mbit psram, cs hold time must only be 0.5T due to the special driving mode.(cs_setup = 0; cs_hold = 0)
4. for new 64Mbit psram, cs hold time is recommended to be 2.5T. (cs_setup = 1, cs_setup_time = 0;cs_hold = 1, cs_hold_time = 1)