vicam: use request_firmware()

Although it wasn't actually using ihex records before, we use the Intel
HEX record format for this firmware -- because that gives us a simple
way to split it into separate chunks internally as we need, without
loading each part as a separate file.

Signed-off-by: Jaswinder Singh <jaswinder@infradead.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>