leds: bcm63138: Add some register defines

The Power LUT (Look-up Table) register base was missing, also
add the bit define for sending serial LED data in reverse order,
and use the BIT() macro to define the bits in the control
register.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20241010-bcm63138-leds-v4-4-cdb80780a555@linaro.org


Signed-off-by: Lee Jones <lee@kernel.org>