Convert CONFIG_SYS_PBSIZE to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_PBSIZE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/origen_defconfig b/configs/origen_defconfig
index 05d9556..b8a6b79 100644
--- a/configs/origen_defconfig
+++ b/configs/origen_defconfig
@@ -23,6 +23,7 @@
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 # CONFIG_SPL_FRAMEWORK is not set
 CONFIG_SYS_PROMPT="ORIGEN # "
+CONFIG_SYS_PBSIZE=1024
 # CONFIG_CMD_XIMG is not set
 CONFIG_CMD_THOR_DOWNLOAD=y
 CONFIG_CMD_DFU=y