lspcon_i2c_spi.c: Add SPI-master support for PS17{5,6}

This adds support for the Parade lspcon usb-c to HDMI protocol
translater part that is i2c-controlled. The support allows the
host to reach the SPI ROM that hangs off the part where it
stores its firmware.

Usage is as follows:
	flashrom -p lspcon_i2c_spi:bus=X
	where X is the bus number.

BUG=b:148746232
BRANCH=none
TEST=tested with following commands, read/write/erase works good.
	flashrom -p lspcon_i2c_spi:bus=7 -r /tmp/foo;
	flashrom -p lspcon_i2c_spi:bus=7 -E;
	flashrom -p lspcon_i2c_spi:bus=7 -w /tmp/foo;

Change-Id: I039e683252cfaf1ffef8694a3e8081b1b6b944f7
Signed-off-by: Shiyu Sun <sshiyu@chromium.org>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/39687
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Edward O'Callaghan <quasisec@chromium.org>
diff --git a/meson_options.txt b/meson_options.txt
index 2831271..a103dc6 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -35,3 +35,4 @@
 option('config_serprog', type : 'boolean', value : true, description : 'serprog')
 option('config_usbblaster_spi', type : 'boolean', value : true, description : 'Altera USB-Blaster dongles')
 option('config_stlinkv3_spi', type : 'boolean', value : true, description : 'STMicroelectronics STLINK-V3')
+option('config_lspcon_i2c_spi', type : 'boolean', value : false, description : 'Parade lspcon USB-C to HDMI protocol translator')