Move setexpr to Kconfig

Another shell scripting command that has not been moved.

Moved using tools/moveconfig.py using these settings:

CMD_SETEXPR bool n y

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/configs/P1025RDB_defconfig b/configs/P1025RDB_defconfig
index 43b38a1..d60af14 100644
--- a/configs/P1025RDB_defconfig
+++ b/configs/P1025RDB_defconfig
@@ -2,3 +2,4 @@
 CONFIG_MPC85xx=y
 CONFIG_TARGET_P1_P2_RDB_PC=y
 CONFIG_SYS_EXTRA_OPTIONS="P1025RDB"
+CONFIG_CMD_SETEXPR=y