novena: Use the default CONFIG_SYS_PBSIZE

Entering the maximum number of characters defined by CONFIG_SYS_CBSIZE into
the console and hitting enter afterwards, causes a hang in the system because
CONFIG_SYS_PBSIZE is not capable of storing the extra characters of the error
message:
"Unknown command '' - try 'help'".

Use the default CONFIG_SYS_PBSIZE definition from config_fallbacks.h to solve
this problem.

Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>

include/configs/novena.h

@@ -58,9 +58,6 @@
 /* U-Boot general configurations */
 #define CONFIG_SYS_LONGHELP
 #define CONFIG_SYS_CBSIZE	1024		/* Console I/O buffer size */
-#define CONFIG_SYS_PBSIZE	\
-	(CONFIG_SYS_CBSIZE + sizeof(CONFIG_SYS_PROMPT) + 16)
-						/* Print buffer size */
 #define CONFIG_SYS_MAXARGS	32		/* Max number of command args */
 #define CONFIG_SYS_BARGSIZE	CONFIG_SYS_CBSIZE
 						/* Boot argument buffer size */