ipq806x: disable cache and fabric devfreq driver to improve stability

It was tested that cache scaling currently cause instability problem.
This is probably caused by a latent misconfiguration that cause the L2
cache to be sourced from the wrong source and runs at an unstable freq
compared to the original QSDK fw.

To improve stability while the problem is bisected, disable the devfreq
drivers with minimal perf penality.

Signed-off-by: Christian Marangi <[email protected]>

target/linux/ipq806x/config-5.15

@@ -127,8 +127,8 @@ CONFIG_DEVFREQ_GOV_PASSIVE=y
 # CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND is not set
 # CONFIG_DEVFREQ_GOV_USERSPACE is not set
 # CONFIG_DEVFREQ_THERMAL is not set
-CONFIG_ARM_KRAIT_CACHE_DEVFREQ=y
-CONFIG_ARM_IPQ806X_FAB_DEVFREQ=y
+# CONFIG_ARM_KRAIT_CACHE_DEVFREQ is not set
+# CONFIG_ARM_IPQ806X_FAB_DEVFREQ is not set
 CONFIG_DMADEVICES=y
 CONFIG_DMA_ENGINE=y
 CONFIG_DMA_OF=y