MIPS: convert CONFIG_SYS_SDRAM_BASE to physical address
Since the beginning, CONFIG_SYS_SDRAM_BASE on MIPS is configured as virtual KSEG0 address. According to the documentation CONFIG_SYS_SDRAM_BASE is a physical address. This is also required to add proper DM_PCI support for MIPS.
- adapt all references and usages of CONFIG_SYS_SDRAM_BASE to create a virtual mapping
- change CONFIG_SYS_SDRAM_BASE in all MIPS board configs to 0x0