coreboot: Add spring chromebook configs

This adds coreboot configuration for the HP Chromebook 11 G1, which is
part of the "google/daisy" mainboard in upstream coreboot. It uses the
shared tree for the "daisy" baseboard.

The config is based on the following defconfig:

    CONFIG_VENDOR_GOOGLE=y
    CONFIG_CBFS_SIZE=0x00400000
    CONFIG_UART_FOR_CONSOLE=3
    CONFIG_BOARD_GOOGLE_DAISY=y
    CONFIG_CONSOLE_CBMEM_BUFFER_SIZE=0x20000
    CONFIG_EC_GOOGLE_CHROMEEC_I2C_BUS=0x4
    CONFIG_UART_PCI_ADDR=0x0
    CONFIG_I2C_TRANSFER_TIMEOUT_US=500000

Untested since I don't have the spring chromebook. This also fails
without a non-free 3rdparty/blobs/cpu/samsung/exynos5250/bl1.bin blob.

Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>

resources/coreboot/daisy_spring/board.cfg

+cbtree="daisy"
+romtype="normal"
+arch="ARMv7"
+payload_uboot="y"