logging: Default to redirecting printk() through it

Default to redirecting the printk() calls through the logging subsystem
using the special logginng log_printk() function that encapsulates raw
strings into buffers and prints them as-is, without any of the logger
additional metadata.

This has 2 advantages:

* Removes potential race conditions between printk() and the logger
backend usage of the UART or any other backend
* Printsk the printk() statements in-order with the rest of the
logs, since now by default printk() messages are deferred

Disadvantages:

* printk() statements are limited in length
* Additional memory consumption by default

Signed-off-by: Carles Cufi <[email protected]>

Author: carlescufi

subsys/logging/Kconfig

@@ -185,6 +185,7 @@ config LOG_MAX_LEVEL
 
 config LOG_PRINTK
 	bool "Enable processing of printk messages."
+	default y
 	help
 	  LOG_PRINTK messages are formatted in place and logged unconditionally.