ppc / layerscape: Clean up CONFIG_SYS_CCSR_DO_NOT_RELOCATE usage

A number of PowerPC platforms define this, for SPL.  To move this to
Kconfig, it needs to be CONFIG_SPL_SYS_CCSR_DO_NOT_RELOCATE, so use
CONFIG_IS_ENABLED() to check for usage.  A number of layerscape
platforms bring this logic from PowerPC, but only need a small part of
it, for the fman driver.  Remove their unused portion at least.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/P2020RDB-PC_36BIT_SPIFLASH_defconfig b/configs/P2020RDB-PC_36BIT_SPIFLASH_defconfig
index 7e9c54b..4740e88 100644
--- a/configs/P2020RDB-PC_36BIT_SPIFLASH_defconfig
+++ b/configs/P2020RDB-PC_36BIT_SPIFLASH_defconfig
@@ -33,6 +33,7 @@
 # CONFIG_SPL_FRAMEWORK is not set
 CONFIG_SPL_MAX_SIZE=0x20000
 CONFIG_SPL_SPI_BOOT=y
+CONFIG_SPL_SYS_CCSR_DO_NOT_RELOCATE=y
 CONFIG_SPL_FLUSH_IMAGE=y
 CONFIG_SPL_ENV_SUPPORT=y
 CONFIG_SPL_I2C=y