Merge https://source.denx.de/u-boot/custodians/u-boot-marvell

- kwboot / kwbimage improvements reducing image size (Pali & Marek)
- a37xx: pinctrl: Correct PWM pins definitions (Marek)
- Convert the Dreamplug Ethernet and SATA to Driver Model (Tony)
- serial: a37xx: DEBUG_UART improvements / fixes (Pali)