config: LoongArch: deepin: set PWM_LOONGSON builtin

deepin inclusion
category: bugfix

users report LL300 Laptop works failed with new driver and kernel,
work around by builtin the pwm driver until loongson find a proper way.

Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
(cherry picked from commit eef9634)
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Author: opsiff

arch/loongarch/configs/deepin_loongarch_desktop_defconfig

@@ -5514,6 +5514,7 @@ CONFIG_PWM_CLK=m
 CONFIG_PWM_DWC=m
 CONFIG_PWM_FSL_FTM=m
 CONFIG_PWM_IQS620A=m
+CONFIG_PWM_LOONGSON=y
 CONFIG_PWM_LP3943=m
 CONFIG_PWM_PCA9685=m
 CONFIG_PWM_STMPE=y