use i2c_master interface

[py06]

I just started using esp-idf for a personal project and found your nice lcd1602 library.
Here is a PR where:

• I removed the dependency on esp_smbus and used i2c_master interface from esp_driver_i2c library provided with esp-idf.
• I also replaced ets_delay_us (not found) with esp_rom_delay_us which was available.

I can now build it and use it with esp-idf 5.5.