powerpc: cpm2 boards: update fcc register logic

In the recent dropping of !NET_MULTI code (commit e2a53458a7ab37523304),
I misread the logic in include/net.h.  Some of it was used by NET_MULTI
code as glue between the multi/non-multi worlds for cpm2 boards.

Rather than restore the block of code, push the logic to the board config
headers where it all belongs.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/configs/IPHASE4539.h b/include/configs/IPHASE4539.h
index 0af43b6..d966306 100644
--- a/include/configs/IPHASE4539.h
+++ b/include/configs/IPHASE4539.h
@@ -82,8 +82,8 @@
  * - Select bus for bd/buffers (see 28-13)
  * - Half duplex
  */
-# define CONFIG_SYS_CMXFCR_MASK	(CMXFCR_FC3 | CMXFCR_RF3CS_MSK | CMXFCR_TF3CS_MSK)
-# define CONFIG_SYS_CMXFCR_VALUE	(CMXFCR_RF3CS_CLK14 | CMXFCR_TF3CS_CLK16)
+# define CONFIG_SYS_CMXFCR_MASK3	(CMXFCR_FC3 | CMXFCR_RF3CS_MSK | CMXFCR_TF3CS_MSK)
+# define CONFIG_SYS_CMXFCR_VALUE3	(CMXFCR_RF3CS_CLK14 | CMXFCR_TF3CS_CLK16)
 # define CONFIG_SYS_CPMFCR_RAMTYPE	0
 # define CONFIG_SYS_FCC_PSMR		(FCC_PSMR_FDE|FCC_PSMR_LPB)