spiFlashdb: add ISSI IS25WP256 and Quad Enable for IS25LP/WP256

The IS25WP256 (0x9d7019, 1.8V variant of the IS25LP256) was missing
from the database, and neither 256Mb part had its Quad Enable bit
described (status register bit 6 per the IS25LP(WP)256D datasheet),
making --enable-quad fail on these parts. Required to boot Xilinx
bitstreams generated with SPI_BUSWIDTH 4.

src/spiFlashdb.hpp

@@ -447,8 +447,25 @@ static std::map <uint32_t, flash_t> flash_list = {
 		.tb_register = FUNCR,
 		.bp_len = 4,
 		.bp_offset = {(1 << 2), (1 << 3), (1 << 4), (1 << 5)},
-		.quad_register = NONER,
+		.quad_register = STATR,
-		.quad_mask = 0,
+		.quad_mask = (1 << 6),
+		.global_lock = false,
+	}},
+	{0x9d7019, {
+		/* https://www.issi.com/WW/pdf/IS25LP(WP)256D.pdf */
+		.manufacturer = "ISSI",
+		.model = "IS25WP256",
+		.nr_sector = 512,
+		.sector_erase = true,
+		.subsector_erase = true,
+		.has_extended = false,
+		.tb_otp = true,
+		.tb_offset = (1 << 1),
+		.tb_register = FUNCR,
+		.bp_len = 4,
+		.bp_offset = {(1 << 2), (1 << 3), (1 << 4), (1 << 5)},
+		.quad_register = STATR,
+		.quad_mask = (1 << 6),
 		.global_lock = false,
 	}},
 	{0xba6015, {