target-xtensa: xtfpga: fix ml605 flash size

ML605 daughterboard has 16MB flash, not 32MB. Change board definition
accordingly.

Cc: qemu-stable@nongnu.org
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
diff --git a/hw/xtensa/xtfpga.c b/hw/xtensa/xtfpga.c
index 2c2f997..d441c02 100644
--- a/hw/xtensa/xtfpga.c
+++ b/hw/xtensa/xtfpga.c
@@ -408,7 +408,7 @@
 {
     static const LxBoardDesc ml605_board = {
         .flash_base = 0xf8000000,
-        .flash_size = 0x02000000,
+        .flash_size = 0x01000000,
         .flash_sector_size = 0x20000,
         .sram_size = 0x2000000,
     };