corstone1000: add nvmxip, fwu-mdata and gpt options

Enable the newest features: nvmxip, fwu-metadata and
gpt. Commands to print the partition info, gpt info
and fwu metadata will be available.

Adjust also env boot script the address of the
bootbank with the new gpt layout, and also remove
the not needed kernel address bank0 and bank1
and retrieve function that would test the bank flag
before and now we are getting the info from the fwu
metadata.

Signed-off-by: Rui Miguel Silva <rui.silva@linaro.org>