uboot-phytec

tftp: update: Allow some parts of the code to be reused when CONFIG_SYS_NO_FLASH is set

Up till now it was impossible to use code from update.c when system
was not equipped with raw FLASH memory.
Such behavior prevented DFU from reusing this code.

Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>