configs: stm32mp15: increase malloc size for pre-reloc

The early malloc usage increased so the associated defined
CONFIG_SYS_MALLOC_F_LEN need to be increased.

For example, for stm32mp15_defconfig and
stm32mp157c-dk2-scmi.dtsi, we have:

Early malloc usage: 280b8 / 80000

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
1 file changed