There are some register description errors in parts of rom/gpio.h
This commit update the incorrect comments in rom/gpio.h And now
esp_rom_gpio.h is recommend instead of rom/gpio.h. So this commit adds
macro SIG_GPIO_OUT_IDX in esp_rom_gpio_connect_out_signal
function and removes the reference to gpio.h in some source files.
Closes https://github.com/espressif/esp-idf/issues/11737
When using PSRAM of rev0, the Flash and PSRAM should use different clock pins. But if using newer PSRAM, this is not necesary. This MR fixed the issue that allocating CLK of PSRAM to the same pin as Flash may crash.
