configs: stm32mp1: Add support for baudrates higher than 115200 for st-link

configs: stm32mp1: Add support for baudrates higher than 115200 for st-link

On STMicroelectronics boards, the UART can reliably go up to
2000000 bauds when connected to the on-board ST-LINK-V2 for STM32MP15

Unfortunately U-Boot will fall back to 115200 unless higher rates are
declared via CONFIG_SYS_BAUDRATE_TABLE.

This patch add the support of higher baudrates on STMicroelectronics
boards with ST-LINK.

Cc: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>