mb/amd/majolica/Kconfig: add EFS SPI settings

This keeps the default of EFS_SPI_SPEED at 66.66Mhz for the non-EM100
case, but switches the EFS_SPI_READ_MODE setting from Dual IO (1-1-2) to
Quad IO (1-1-4) for the non-EM100 case. This patch adds a special config
for the EM100 emulator case that has limited SPI frequency support.

Tested on Majolica by Martin.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I8996c2bf606ccd21686092beac8d96b22c0b7869
Reviewed-on: https://review.coreboot.org/c/coreboot/+/56815
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/amd/majolica/Kconfig

@@ -53,4 +53,12 @@ config CHROMEOS
 	# Use default libpayload config
 	select LP_DEFCONFIG_OVERRIDE if PAYLOAD_DEPTHCHARGE
 
+config EFS_SPI_READ_MODE
+	default 0 if EM100 # Normal read mode
+	default 3          # Quad IO (1-1-4)
+
+config EFS_SPI_SPEED
+	default 3 if EM100 # 16.66 MHz
+	default 0          # 66.66 MHz
+
 endif # BOARD_AMD_MAJOLICA