leds: pca955x: Optimize probe LED selection

leds: pca955x: Optimize probe LED selection

Previously, the probe function might do up to 32 reads and writes
to the same 4 registers to program the LED selection. Reduce this to
a maximum of 5 operations by accumulating the changes to the LED
selection and comparing with the previous value to write the
selection if different.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20250212143038.1416501-4-eajames@linux.ibm.com
Signed-off-by: Lee Jones <lee@kernel.org>