Replaced GMBUS WRITE TODO stub with real implementation.
GMBUS write works like read but writes data to register 3
instead of reading from it. Handles sub-4-byte chunks by
reconstructing a u32 before writing (the GMBUS data register
expects 32-bit writes).
Cross-referenced with Linux 7.1 i915 display/intel_gmbus.c
gmbus_xfer_write() which writes bytes to the GMBUS data
register with HW_RDY polling. Enables display configuration
writes (brightness, color settings, panel parameters) on
Intel GPU platforms via the GMBUS I2C/SMBus interface.
Red Bear OS
0f4f8cebf3