powerpc: Drop unreferenced CONFIG_* defines

The following config symbols are only defined once and never referenced
anywhere else:

CONFIG_CYRUS
CONFIG_IDS8313
CONFIG_MPC8308_P1M
CONFIG_MPC8308RDB
CONFIG_MPC8349EMDS
CONFIG_MPC8349ITXGP
CONFIG_SBC8349
CONFIG_SBC8548
CONFIG_SBC8641D
CONFIG_TQM834X
CONFIG_VE8313
CONFIG_XPEDITE5140
CONFIG_XPEDITE5200
CONFIG_XPEDITE550X

Most of them are config symbols named after the respective boards which
seems to have been a standard practice at some point.

Signed-off-by: Tuomas Tynkkynen <tuomas@tuxera.com>
Acked-by: Mario Six <mario.six@gdsys.cc>
diff --git a/configs/MPC8349ITXGP_defconfig b/configs/MPC8349ITXGP_defconfig
index 319141d..97dc8e7 100644
--- a/configs/MPC8349ITXGP_defconfig
+++ b/configs/MPC8349ITXGP_defconfig
@@ -3,7 +3,7 @@
 CONFIG_TARGET_MPC8349ITX=y
 CONFIG_OF_BOARD_SETUP=y
 CONFIG_OF_STDOUT_VIA_ALIAS=y
-CONFIG_SYS_EXTRA_OPTIONS="MPC8349ITXGP,SYS_TEXT_BASE=0xFE000000"
+CONFIG_SYS_EXTRA_OPTIONS="SYS_TEXT_BASE=0xFE000000"
 CONFIG_BOOTDELAY=6
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="root=/dev/nfs rw nfsroot=:/nfsroot/rootfs ip=::::mpc8349emitxgp:eth0:off console=ttyS0,115200"