Disable PSERIES in petitboot kernel

Saves about 170kb:
-rwxr-xr-x 1 stewart users 14218342 Aug 18 15:58 zImage.epapr
-rwxr-xr-x 1 stewart users 14046310 Aug 18 16:15 zImage.epapr

The only place pseries is used is in petitboot-tests, so we
*should* be okay to disable this

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
diff --git a/openpower/configs/linux/skiroot_defconfig b/openpower/configs/linux/skiroot_defconfig
index d022a0c..6ca2e6b 100644
--- a/openpower/configs/linux/skiroot_defconfig
+++ b/openpower/configs/linux/skiroot_defconfig
@@ -1,5 +1,7 @@
 CONFIG_PPC64=y
 CONFIG_ALTIVEC=y
+CONFIG_PPC_POWERNV_RTAS=n
+CONFIG_PPC_PSERIES=n
 CONFIG_VSX=y
 CONFIG_SMP=y
 CONFIG_NR_CPUS=2048
@@ -79,7 +81,6 @@
 CONFIG_SCSI_BNX2_ISCSI=y
 CONFIG_BE2ISCSI=y
 CONFIG_SCSI_MPT2SAS=y
-CONFIG_SCSI_IBMVSCSI=y
 CONFIG_SCSI_SYM53C8XX_2=y
 CONFIG_SCSI_SYM53C8XX_DMA_ADDRESSING_MODE=0
 CONFIG_SCSI_IPR=y
@@ -121,7 +122,6 @@
 CONFIG_CHELSIO_T1=y
 CONFIG_BE2NET=y
 CONFIG_S2IO=y
-CONFIG_IBMVETH=y
 CONFIG_E100=y
 CONFIG_E1000=y
 CONFIG_E1000E=y