Revert "leds-pca955x: Remove the unused function pca95xx_num_led_regs()"

This reverts commit 38bcb51.

This function is needed by the hardware blink support just introduced.
Also rename the function to pca955x_num_led_regs() to match the rest of
the functions in the driver.

Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20250221155144.2109806-1-eajames@linux.ibm.com
Signed-off-by: Lee Jones <lee@kernel.org>

Author: Eddie James

drivers/leds/leds-pca955x.c

@@ -147,6 +147,12 @@ static inline int pca955x_num_input_regs(int bits)
 	return (bits + 7) / 8;
 }
 
+/* 4 bits per LED selector register */
+static inline int pca955x_num_led_regs(int bits)
+{
+	return (bits + 3)  / 4;
+}
+
 /*
  * Return an LED selector register value based on an existing one, with
  * the appropriate 2-bit state value set for the given LED number (0-3).