Corrected sram_size for L496x/L4A6x  devices
(Closes
@@ -6,7 +6,7 @@ chip_id 0x461 // STM32_CHIPID_L496x_L4A6x
flash_type L4_L4P
flash_size_reg 0x1fff75e0
flash_pagesize 0x800 // 2 KB
-sram_size 0x40000 // 256 KB
+sram_size 0x50000 // 320 KB
bootrom_base 0x1fff0000
bootrom_size 0x7000 // 28 KB
option_base 0x1fff7800 // STM32_L4_OPTION_BYTES_BASE
