treewide: move bi_dram[] from bd to gd

Currently, the bi_dram[] information is stored in the board info
structure (bd). Because bd is only valid after reserve_board(),
dram_init_banksize() must be called late in the initialization process.
This limitation is problematic, as it forces us to rely on a variety of
bespoke functions to determine board RAM, bank memory sizes, and other
early setup requirements.

By moving bi_dram[] into the global data (gd), we can run it earlier.
This is particularly convenient since boards define their own
dram_init_banksize() routines, which do not always rely on parsing
Device Tree (DT) memory nodes.

Additionally, U-Boot defaults to relocating to the top of the first memory
bank. While boards currently use custom functions to override this
behavior, having the DRAM bank information available earlier in gd makes
relocating to a different bank trivial and standardizes the process.

Reviewed-by: Anshul Dalal <anshuld@ti.com>
Tested-by: Michal Simek <michal.simek@amd.com> # Versal Gen 2 Vek385
Tested-by: Anshul Dalal <anshuld@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Tested-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org>

test/cmd/bdinfo.c

@@ -138,16 +138,15 @@ static int lmb_test_dump_all(struct unit_test_state *uts)
 
 static int bdinfo_check_mem(struct unit_test_state *uts)
 {
-	struct bd_info *bd = gd->bd;
 	int i;
 
 	for (i = 0; i < CONFIG_NR_DRAM_BANKS; ++i) {
-		if (bd->bi_dram[i].size) {
+		if (gd->dram[i].size) {
 			ut_assertok(test_num_l(uts, "DRAM bank", i));
 			ut_assertok(test_num_ll(uts, "-> start",
-						bd->bi_dram[i].start));
+						gd->dram[i].start));
 			ut_assertok(test_num_ll(uts, "-> size",
-						bd->bi_dram[i].size));
+						gd->dram[i].size));
 		}
 	}