SECURE BOOT - Removed deletion of TLB entries code

Boot ROM code creates TLB entries for 3.5G space before entering
the u-boot. Earlier we were deleting these entries after early
initialization of CPU. In recent past, code has been added
to invalidate all these entries before relocation of u-boot code.
So this code to delete TLB entries after CPU initialization
is no longer required.

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Acked-by: Matthew McClintock <msm@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>