board: ti: Pull redundant DDR functions to a common location and Fixup DDR size when...

board: ti: Pull redundant DDR functions to a common location and Fixup DDR size when ECC is enabled

As there are few redundant functions in board/ti/*/evm.c files, pull
them to a common location of access to reuse and include the common file
to access the functions.

Call k3-ddrss driver through fixup_ddr_driver_for_ecc() to fixup the
device tree and resize the available amount of DDR, if ECC is enabled.
Otherwise, fixup the device tree using the regular
fdt_fixup_memory_banks().

Also call dram_init_banksize() after every call to
fixup_ddr_driver_for_ecc() is made so that gd->bd is populated
correctly.

Ensure that fixup_ddr_driver_for_ecc() is agnostic to the number of DDR
controllers present.

Signed-off-by: Santhosh Kumar K <s-k6@ti.com>
Signed-off-by: Neha Malcom Francis <n-francis@ti.com>
Reviewed-by: Wadim Egorov <w.egorov@phytec.de>