feat: enable PWM_RP1 drivers for Raspberry Pi 5 fan control

Enable CONFIG_PWM_RP1 and CONFIG_PWM_PIO_RP1 in the arm64 kernel
config. These in-tree drivers are required for the Raspberry Pi 5
dedicated 4-pin PWM fan header to function.

Without them, the cooling_fan device tree node cannot acquire a PWM
channel and the fan probe is permanently deferred:

  platform cooling_fan: deferred probe pending: pwm-fan: Could not get PWM

Fixes: #1499

Author: blacksd

kernel/build/config-arm64

@@ -9098,6 +9098,8 @@ CONFIG_PWM_MESON=y
 # CONFIG_PWM_OMAP_DMTIMER is not set
 # CONFIG_PWM_PCA9685 is not set
 CONFIG_PWM_RASPBERRYPI_POE=y
+CONFIG_PWM_RP1=y
+CONFIG_PWM_PIO_RP1=y
 # CONFIG_PWM_RENESAS_RCAR is not set
 # CONFIG_PWM_RENESAS_TPU is not set
 CONFIG_PWM_ROCKCHIP=y