ppc: Remove sbc8641d board

This board has not been converted to CONFIG_DM_PCI by the deadline and is
also missing conversion to CONFIG_DM.  Remove it.  This is also the last
of the ARCH_MPC8641/MPC8610 platforms, so remove that support as well.

Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Priyanka Jain <priyanka.jain@nxp.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/env/Kconfig b/env/Kconfig
index c06b8ba..691f4d4 100644
--- a/env/Kconfig
+++ b/env/Kconfig
@@ -85,7 +85,7 @@
 	default y if M548x || M547x || M5282
 	default y if MCF532x || MCF52x2
 	default y if MPC86xx || MPC83xx
-	default y if ARCH_MPC8548 || ARCH_MPC8641
+	default y if ARCH_MPC8548
 	default y if SH && !CPU_SH4
 	help
 	  Define this if you have a flash device which you want to use for the