cid_tab: initial addition, Boundary Devices board

cid_tab: delay 3P7V rail turn on
cid_tab: turn off boost before poweroff
cid_tab: add  CONFIG_SPI_FLASH_GIGADEVICE: to defconfigs
cid_tab: tamper support checking TAMPER pin
cid_tab: use common ddr script
cid_tab: port to v2018.07

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>

cid_tab: fix TP74 pad configuration

cid_tab: add key combination to start fastboot
cid_tab_q2g_defconfig: reduce bootdelay to 0
cid_tab: limit boot sequence to eMMC

Signed-off-by: Gary Bisson <gary.bisson@boundarydevices.com>