lmb: notify when adjacent regions are added

lmb: notify when adjacent regions are added

lmb_add_region() returns a positive integer if the added regions causes
existing regions to be coalesced. We still want to notify the EFI
subsystem about these added regions though, so adjust lmb_add() to only
bail on errors.

This fixes EFI memory allocation on boards with adjacent memory banks as is the
case on several Qualcomm boards like the RB3 Gen 2.

Fixes: 2f6191526a13 (lmb: notify of any changes to the LMB memory map)
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>
Reviewed-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>