Add configuration and driver support for the SSD1681 1.54 inch e-paper display,
including the necessary waveforms and settings for proper operation. This extends
the existing SSD1680 e-paper driver to accommodate the new display module.
The changes involve updates to the Kconfig file for additional configuration options,
modifications to the driver implementation in ssd1680.c to include SSD1681 specific
logic, and updates to the header file ssd1680.h to reflect the added support.
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>