1. remove use EID to distinguish psram voltage
2. 1V8 64Mbit psram and 3V3 64Mbit psram use the same psram driver(standard spi interface)
3. set cs hold time register as 1
1. Add reading psram EID.
2. Configure different clock mode for different EID.
3. add API to get psram size and voltage.
4. Remove unnecessary VSPI claim.
For 32MBit@1.8V and 64MBit@3.3V psram, there should be 2 extra clock cycles after CS get high level.
For 64MBit@1.8 psram, we can just use standard SPI protocol to drive the psram. We also need to increase the HOLD time for CS in this case.
EID for psram:
32MBit 1.8v: 0x20
64MBit 1.8v: 0x26
64MBit 3.3v: 0x46
Some frameworks based on ESP-IDF need to be able to decide whether to
initialize SPI RAM after the application has started. This change splits
out part of esp_spiram_init which manipulate cache MMU into a separate
function. Applications can disable cache, call esp_spiram_init_cache,
re-enable cache, and then call esp_spiram_init.
Disabling and re-enabling the cache can be achieved using functions
provided in esp_spi_flash.h.
