arm64: versal: Drop default definitions of CONFIG_SYS_PBSIZE

It is default value which had been converted by commit 432e3980
("include/configs: drop default definitions of CONFIG_SYS_PBSIZE"). That's
why also remove it.
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>

include/configs/xilinx_versal.h

@@ -41,8 +41,6 @@
 /* Monitor Command Prompt */
 /* Console I/O Buffer Size */
 #define CONFIG_SYS_CBSIZE		2048
-#define CONFIG_SYS_PBSIZE		(CONFIG_SYS_CBSIZE + \
-					sizeof(CONFIG_SYS_PROMPT) + 16)
 #define CONFIG_SYS_BARGSIZE		CONFIG_SYS_CBSIZE
 #define CONFIG_SYS_MAXARGS		64