You need to modify and rebuild atf and u-boot source code to redirect UART1 to UART2.
In atf, plat/nxp/soc-ls1028a/include/soc.h,
#define NXP_CONSOLE_ADDR NXP_UART_ADDR
modify to
#define NXP_CONSOLE_ADDR NXP_UART1_ADDR
In u-boot source code, please add the following line in configs/ls1028ardb_tfa_defconfig
CONFIG_CONS_INDEX=2
Then rebuild u-boot and atf source code to generate new atf images and program them to the target board.