ARM: exynos_defconfig: Enable Panfrost and Lima drivers

Enable support for Mali GPU with Panfrost and Lima drivers.  Most of
Exynos chipsets come with Mali GPUs:
1. Mali 400 (Exynos3250, Exynos4210, Exynos4412),
2. Mali T628 (Exynos542x).
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/configs/exynos_defconfig

@@ -212,6 +212,8 @@ CONFIG_DRM_NXP_PTN3460=y
 CONFIG_DRM_PARADE_PS8622=y
 CONFIG_DRM_SII9234=y
 CONFIG_DRM_TOSHIBA_TC358764=y
+CONFIG_DRM_LIMA=y
+CONFIG_DRM_PANFROST=y
 CONFIG_LCD_CLASS_DEVICE=y
 CONFIG_LCD_PLATFORM=y
 CONFIG_BACKLIGHT_PWM=y
@@ -284,7 +286,6 @@ CONFIG_CROS_EC_SPI=y
 CONFIG_COMMON_CLK_MAX77686=y
 CONFIG_COMMON_CLK_S2MPS11=y
 CONFIG_EXYNOS_IOMMU=y
-CONFIG_PM_DEVFREQ=y
 CONFIG_DEVFREQ_GOV_PERFORMANCE=y
 CONFIG_DEVFREQ_GOV_POWERSAVE=y
 CONFIG_DEVFREQ_GOV_USERSPACE=y