board: ti: am43xx: print unsupported board name

when porting u-boot to a new am43xx board, it
helps to know the name of the current unsupported
board so we don't have to hunt for design documents
to figure out what's written in the EEPROM.

Signed-off-by: Felipe Balbi <balbi@ti.com>

board/ti/am43xx/board.c

@@ -260,7 +260,7 @@ const struct dpll_params *get_dpll_ddr_params(void)
 	else if (board_is_gpevm())
 		return &gp_evm_dpll_ddr;
 
-	puts(" Board not supported\n");
+	printf(" Board '%s' not supported\n", am43xx_board_name);
 	return NULL;
 }