Adoption of U-Boot commit:

| commit b4a2cdc
| Author: Marek Vasut <marex@denx.de>
| Date:   Tue Oct 15 18:26:57 2019 +0200
|
|     arm: mxs: Increase VDDD voltage to match specification
|
|     According to IMX28CEC rev. 4, 10/2018, Table 15. Recommended Operating
|     Conditions, page 16, the VDDD should be set to 1.55V when the CPU is
|     operating at 454MHz. This is the case in U-Boot, hence increase the
|     VDDD voltage. This fixes instability when performing TFTP transfers.
|     Increase the brownout threshold to 1.4V. The documentation recommends
|     1.45V setting for the brownout, however, this triggers failure during
|     power block init, so keep the brownout slightly lower.
|
|     Signed-off-by: Marek Vasut <marex@denx.de>
|     Cc: Stefano Babic <sbabic@denx.de>
|     Reviewed-by: Fabio Estevam <festevam@gmail.com>

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>