uart: support alloc driver object in SRAM
uart: support alloc driver object in SRAM

If CONFIG_UART_ISR_IN_IRAM is on, which means user hope the uart
interrupt can still be serviced even when cache is diabled (e.g.
writing to flash). In that case, the driver should make sure to
put the all related objects into SRAM, avoid putting them in the PSRAM.

Closes https://github.com/espressif/esp-idf/issues/7044
Closes https://github.com/espressif/esp-idf/pull/7355

espressif/esp-idf,espressif/esp-idf,espressif/esp-idf,espressif/esp-idf