Convert CONFIG_SYS_LOAD_ADDR to Kconfig

Now that we have consistent usage, migrate this symbol to Kconfig.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/configs/mt7620_mt7530_rfb_defconfig b/configs/mt7620_mt7530_rfb_defconfig
index 5e9d267..9751baa 100644
--- a/configs/mt7620_mt7530_rfb_defconfig
+++ b/configs/mt7620_mt7530_rfb_defconfig
@@ -16,6 +16,7 @@
 CONFIG_RESTORE_EXCEPTION_VECTOR_BASE=y
 CONFIG_MIPS_BOOT_FDT=y
 CONFIG_DEBUG_UART=y
+CONFIG_SYS_LOAD_ADDR=0x80010000
 CONFIG_FIT=y
 # CONFIG_ARCH_FIXUP_FDT_MEMORY is not set
 CONFIG_SPL_SYS_MALLOC_SIMPLE=y