pwm: atmel-tcb: Switch to new binding

The PWM is now a subnode of the used TCB. This is cleaner and it mainly
allows to stop wasting TCB channels when only 2 or 4 PWMs are used.

This also removes the atmel_tclib dependency

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-pwm@vger.kernel.org
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/Kconfig

@@ -75,7 +75,8 @@ config PWM_ATMEL_HLCDC_PWM
 
 config PWM_ATMEL_TCB
 	tristate "Atmel TC Block PWM support"
-	depends on ATMEL_TCLIB && OF
+	depends on OF
+	select REGMAP_MMIO
 	help
 	  Generic PWM framework driver for Atmel Timer Counter Block.