This patch provides four configurations which can support U-Boot SPL
to boot from RAM or FLASH and then boot FIT image including OpenSBI
FW_DYNAMIC firmware and U-Boot proper images from RAM or MMC boot devices.

With ae350_rv[32|64]_spl_defconfigs:

U-Boot SPL will be loaded by gdb or FSBL and runs in RAM in machine mode
and then load FIT image from RAM device on AE350.

With ae350_rv[32|64]_spl_xip_defconfigs:

U-Boot SPL can be burned into SPI flash and run in flash in machine mode
and then load FIT image from SPI flash or MMC device on AE350.
Signed-off-by: NRick Chen <rick@andestech.com>
Cc: KC Lin <kclin@andestech.com>
Cc: Alan Kao <alankao@andestech.com>

Add two defconfigs to support AE350 SMP booting from flash.
Signed-off-by: NRick Chen <rick@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>
Reviewed-by: NLukas Auer <lukas.auer@aisec.fraunhofer.de>

Remove cpu name from the defconfig naming.
Because other cpus maybe run on AE350 platform.
So only use platfrom name in defconfig naming
will be better.

Also sync MAINTAINERS:
Rename
a25-ae350_32_defconfig as ae350_rv32_defconfig
ax25-ae350_64_defconfig as ae350_rv64_defconfig
Signed-off-by: NRick Chen <rick@andestech.com>
Cc: Greentime Hu <greentime@andestech.com>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>

Rename
 nx25 as ax25
 ae250 as ae350
 nx25-ae250 as ax25-ae350
 including filename, variable, string and definition.
Signed-off-by: NRick Chen <rick@andestech.com>
Signed-off-by: NRick Chen <rickchen36@gmail.com>
Cc: Greentime Hu <green.hu@gmail.com>