stingray: Fix board configuration typo.

Default board configuration was set to bcm958742k which is not present
in current codebase. This causes a default platform build to fail.
Changing to bcm958742t.
Signed-off-by: Max Shvetsov <maksims.svecovs@arm.com>
Change-Id: Ie24f94ef0ef316ff56fe142df5de45d70ba93c28

plat/brcm/board/stingray/platform.mk

@@ -70,7 +70,7 @@ $(eval $(call add_define,USE_DDR))
 endif
 
 ifeq (${BOARD_CFG},)
-BOARD_CFG := bcm958742k
+BOARD_CFG := bcm958742t
 endif
 
 # Use PAXB