nitrogen6_som2: initial addition, Boundary Devices board

nitrogen6_som2: add IMX_VD38_AUO_B101EW05
nitrogen6_som2: add IMX_VD38_DT070BTFT
nitrogen6_som2: calibrate 1G boards, sample size of only 4
nitrogen6_som2: nitrogen6q_som2_4g.cfg: remove redefine of CONFIG_MX6Q
nitrogen6_som2: disable mirroring
nitrogen6_som2: 4G calibration
nitrogen6_som2: add atheros AR8035 ethernet phy choice
nitrogen6_som2: increase drive strength for usdhc2/3, sd card/wifi
nitrogen6_som2.h: CONFIG_IPUV3_CLK 264000000
nitrogen6_som2: use nitrogen6x clocks.cfg/ddr-setup.cfg
nitrogen6_som2: explicit fbp_detect_i2c
nitrogen6_som2: add wlmac
nitrogen6_som2: verify port in board_ehci_hcd_init
nitrogen6_som2: use boundary.h
nitrogen6_som2: setup rgb_gpio_pads in board_early_init_f
nitrogen6_som2: add CONFIG_SPI_FLASH_SPANSION
nitrogen6q_som2: add CONFIG_CMD_GPIO
nitrogen6q_som2: rename some cfg files
nitrogen6_som2: add nitrogen6_som2_s512m_defconfig
nitrogen6_som2: add nitrogen6_som2_s1g_defconfig
nitrogen6_som2: nitrogen6_som2_s1g_defconfig add CONFIG_BLOCK_CACHE
nitrogen6_som2: use common code for eth init
nitrogen6_som2: eth.c now in common directory
nitrogen6_som2: move misc_init_r/do_kbd to common
nitrogen6_som2: move mmc_init/ dram_init/ overwrite_console/ common_board_init/ splash_screen_prepare/ board_cfb_skip to common
nitrogen6_som2: use common 1066mhz_4x256mx16.cfg
nitrogen6_som2: use common 1066mhz_4x128mx16.cfg
nitrogen6_som2: use common 800mhz_4x128mx16.cfg
nitrogen6_som2: add  CONFIG_SPI_FLASH_GIGADEVICE: to defconfigs
nitrogen6_som2: fix DEFCONFIG nitrogen6qp_som2_4g
nitrogen6_som2: 800mhz_2x128mx16.cfg: remove _P1 accesses
nitrogen6_som2: 800mhz_2x256mx16.cfg: remove _P1 accesses
nitrogen6_som2: 800mhz_2x128mx16.cfg: use common values

CFG0: 0x40435323 to 0x3f435333
tRFC - 65 to 64 clocks
tFAW - 19 to 20 clocks

CFG1: 0xB66E8D63 to 0xb68e8b63
tRC from 20 to 21 clocks
tWR from 7 to 6 clocks

MR0: 0x13208030 to 0x15208030
tWR from 5 to 6 clocks

nitrogen6_som2: 800mhz_2x256mx16.cfg: :use common values

MDCFG0: from 0x696c5323 to 0x666a5333
tRFC - from 106 to 103 clocks
tXS - from 109 to 107 clocks
tFAW - from 19 to 20 clocks

MDCFG1: from 0xb66e8d63 to 0xb68e8b63
tRC - from 20 to 21 clocks
tWR - from 7 clocks to 6 clocks

MDCFG2: from 0x01ff00dc to 0x01ff00db
tRRD from 5 to 4 clocks

MDRWD: from 0x000026d2 to 0x0f9f26d2
restore unused field to default value

MDOR: from 0x006c1023 to 0x006a1023
tXPR - from 109 to 107 clocks

MR0: from 0x13208030 to 0x15208030
tWR - from 5 to 6 clocks

nitrogen6_som2: use common ddr scripts
nitrogen6_som2: port to v2018.07

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

nitrogen6_som2.h: add basic fastboot support
nitrogen6_som2: add secure boot option
nitrogen6_som2: fix PHY address mask
nitrogen6_som2: declare TC358743 interrupt as input
nitrogen6_som2: add 4GB 6QP version
nitrogen6_som2: update to v2017.01
nitrogen6_som2: update to v2017.03
nitrogen6_som2: add DL variant with 1GB of RAM

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