am335x: configs: Use ISW_ENTRY_ADDR to set SPL_TEXT_BASE

The SPL load address changes based on boot type in HS devices,
ISW_ENTRY_ADDR is used to set this address for AM43xx based SoCs
for similar reasons. Add this same logic for AM33xx devices.

Also make the default value for ISW_ENTRY_ADDR correct for GP
devices based on SoC, HS devices already pick the correct
value in their defconfig.

Signed-off-by: Andrew F. Davis <afd@ti.com>
diff --git a/include/configs/ti_am335x_common.h b/include/configs/ti_am335x_common.h
index d841b3f..809d015 100644
--- a/include/configs/ti_am335x_common.h
+++ b/include/configs/ti_am335x_common.h
@@ -56,7 +56,7 @@
  * supports X-MODEM loading via UART, and we leverage this and then use
  * Y-MODEM to load u-boot.img, when booted over UART.
  */
-#define CONFIG_SPL_TEXT_BASE		0x402F0400
+#define CONFIG_SPL_TEXT_BASE		CONFIG_ISW_ENTRY_ADDR
 #define CONFIG_SYS_SPL_ARGS_ADDR	(CONFIG_SYS_SDRAM_BASE + \
 					 (128 << 20))