counter: stm32-timer-cnt: Use TIM_DIER_CCxIE(x) instead of TIM_DIER_CCxIE(x)

These two defines have the same purpose and this change doesn't
introduce any differences in drivers/counter/stm32-timer-cnt.o.

The only difference between the two is that

	TIM_DIER_CC_IE(1) == TIM_DIER_CC2IE

while

	TIM_DIER_CCxIE(1) == TIM_DIER_CC1IE

. That makes it necessary to have an explicit "+ 1" in the user code,
but IMHO this is a good thing as this is the code locatation that
"knows" that for software channel 1 you have to use TIM_DIER_CC2IE
(because software guys start counting at 0, while the relevant hardware
designer started at 1).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Acked-by: William Breathitt Gray <wbg@kernel.org>
Link: https://lore.kernel.org/r/126bd153a03f39e42645573eecf44ffab5354fc7.1718791090.git.u.kleine-koenig@baylibre.com


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