configs: ls1012afrwy: adjust env kernel_addr_r

Adjust environment kernel_addr_r from 0x96000000 to 0x92000000
to fix a bug that failed to boot kernel for ls1012afrwy with 512MiB RAM,
=> tftpboot $kernel_addr_r Image (Image size is 36 MiB)
TFTP error: trying to overwrite reserved memory...

Signed-off-by: Biwen Li <biwen.li@nxp.com>
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>