counter: 104-quad-8: Add const qualifier for functions_list array

The struct counter_count functions_list member expects a const enum
counter_count_function array. This patch adds the const qualifier to the
quad8_count_functions_list to match functions_list.
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/6847da7553208e7f2554e6c7688e2021f7e19716.1623201081.git.vilhelm.gray@gmail.comSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/counter/104-quad-8.c

@@ -193,7 +193,7 @@ enum quad8_count_function {
 	QUAD8_COUNT_FUNCTION_QUADRATURE_X4
 };
 
-static enum counter_count_function quad8_count_functions_list[] = {
+static const enum counter_count_function quad8_count_functions_list[] = {
 	[QUAD8_COUNT_FUNCTION_PULSE_DIRECTION] = COUNTER_COUNT_FUNCTION_PULSE_DIRECTION,
 	[QUAD8_COUNT_FUNCTION_QUADRATURE_X1] = COUNTER_COUNT_FUNCTION_QUADRATURE_X1_A,
 	[QUAD8_COUNT_FUNCTION_QUADRATURE_X2] = COUNTER_COUNT_FUNCTION_QUADRATURE_X2_A,