Add BP5758 I2C LED driver and product example

[Copilot]

Implements support for BP5758, a 5-channel I2C constant current LED driver IC (address 0x15), and provides a product example for color temperature control.

Driver Implementation

components/light/bp5758/

• I2C protocol implementation with configurable current limiting (90mA per channel)
• Channel mapping: 0-2 (RGB), 3-4 (Cold/Warm white)
• Explicit pin registration: channel 0=SDA, channel 1=SCL
• Integer division with rounding for precision: (value * max + 127) / 255

Light driver integration

• Added LIGHT_DEVICE_TYPE_BP5758 enum value
• Added bp5758_io struct to light_io_conf_t union for I2C pins
• Kconfig option for device type selection
• Support for all channel combinations: 1CH, 2CH CW, 3CH RGB, 5CH RGBCW

Product Example

products/light_cw_bp5758/

• Based on light_cw_pwm structure adapted for I2C control
• Default configuration: 2CH CW (GPIO6 SDA, GPIO7 SCL)
• Supports color temperature adjustment (2700K-6500K)

light_driver_config_t cfg = {
    .device_type = LIGHT_DEVICE_TYPE_BP5758,
    .channel_comb = LIGHT_CHANNEL_COMB_2CH_CW,
    .io_conf = {
        .bp5758_io = {
            .sda_io = GPIO_NUM_6,
            .scl_io = GPIO_NUM_7,
        },
    },
};

Notes

Current implementation uses current control registers for brightness scaling. Production deployments should verify register addresses against the specific BP5758 variant datasheet, as grayscale registers may differ. Individual I2C transactions per channel can be batched if protocol supports it.

Original prompt

Create an example for a light using bp5758 as the led driver

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