part: add GW2A(R)-18(C)

Add JTAG ID code for GW2A(R)-18(C), tested with GW2A-18C on Sipeed Tang
Primer 20K.

Signed-off-by: Icenowy Zheng <uwu@icenowy.me>

doc/FPGAs.yml

@@ -54,6 +54,7 @@ Gowin:
      - GW1NS-2C
      - GW1NSR-4C
      - GW1NZ-1
+     - GW2A-18C
     URL: https://www.gowinsemi.com/en/product/detail/2/
     Memory: OK
     Flash: IF

src/part.hpp

@@ -143,6 +143,7 @@ static std::map <uint32_t, fpga_model> fpga_list = {
 	{0x0100681b, {"Gowin", "GW1NZ", "GW1NZ-1", 8}},
 	{0x0300181b, {"Gowin", "GW1NS", "GW1NS-2C", 8}},
 	{0x0100981b, {"Gowin", "GW1NSR", "GW1NSR-4C", 8}},
+	{0x0000081b, {"Gowin", "GW2A", "GW2A(R)-18(C)", 8}},
 
 	/* keep highest nibble to prevent confusion with Efinix T4/T8 IDCODE */
 	{0x20000001, {"colognechip", "GateMate Series", "GM1Ax", 6}},