qiprog: Implement reading chip contents to file

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
qiprog: Implement chip verify operation

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
qiprog: Identify the flash chip's size based on its ID

Generally, there is no reliable way to probe a chip's size, so the best way
to find it is to look it up base on the device's manufacturer and vendor
ID. Use a minimal table for this.

Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>