image_types_gbmc_dynamic: add aspeed-g7 config Per Aspeed SDK user guide 9.3, it's 0x100000000 for AST27XX. https://screenshot.googleplex.com/8QacbNfbHXd3FFA Tested: Built and booted into console. Google-Bug-Id: 351901052 Google-Bug-Id: 388473031 Change-Id: Ib60d3ef0a125d0bc6945c39d8ae9c470de59460c Signed-off-by: Tom Tung <tomtung@google.com>