arch: m68k: Use existing CONFIG_MCFTMR instead of CFG_MCFTMR

There is an existing CONFIG_MCFTMR Kconfig symbol,
use it and drop all other instances of CFG_MCFTMR.
This duality is likely a result of bogus conversion
to Kconfig.

Fixes: 7ff7b46e6ce ("m68k: rename CONFIG_MCFTMR to CFG_MCFTMR")
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/board/freescale/m53017evb/README b/board/freescale/m53017evb/README
index 5d5c5e7..34f05f3 100644
--- a/board/freescale/m53017evb/README
+++ b/board/freescale/m53017evb/README
@@ -87,7 +87,7 @@
 CONFIG_SYS_FEC0_MIIBASE		-- Set FEC0 MII base register
 MCFFEC_TOUT_LOOP		-- set FEC timeout loop
 
-CFG_MCFTMR			-- define to use DMA timer
+CONFIG_MCFTMR			-- define to use DMA timer
 
 CONFIG_SYS_I2C_FSL		-- define to use FSL common I2C driver
 CONFIG_SYS_I2C_SOFT		-- define for I2C bit-banged