mx51evk: Remove unneeded comment

Looks like the original comment came from a copy and paste from mx31ads.h.

It does not have a context on mx51evk anymore, so delete it.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>

include/configs/mx51evk.h

@@ -34,10 +34,6 @@
 #define CONFIG_SYS_TEXT_BASE	0x97800000
 
 #include <asm/arch/imx-regs.h>
-/*
- * Disabled for now due to build problems under Debian and a significant
- * increase in the final file size: 144260 vs. 109536 Bytes.
- */
 
 #define CONFIG_CMDLINE_TAG			/* enable passing of ATAGs */
 #define CONFIG_SETUP_MEMORY_TAGS