mb/lenovo/haswell: Enable VBOOT_VBNV_FLASH

To deprecate VBOOT_VBNV_CMOS [1], replace VBOOT_VBNV_CMOS with
VBOOT_VBNV_FLASH for Haswell.

Currently BOOT_DEVICE_SPI_FLASH_NO_EARLY_WRITES is selected for
CPU_INTEL_HASWELL (see [2]). However, there seems to be no
particular reason on those platforms. Flashconsole works on Broadwell,
at least, and it writes to flash as early as bootblock. Therefore,
remove BOOT_DEVICE_SPI_FLASH_NO_EARLY_WRITES, so that VBOOT_VBNV_FLASH
can be enabled.

[1] https://issuetracker.google.com/issues/235293589
[2] commit 6c2568f4f5 (CB:45740)
    drivers/spi: Add BOOT_DEVICE_SPI_FLASH_NO_EARLY_WRITES config

BUG=b:235293589
TEST=./util/abuild/abuild -t LENOVO_THINKPAD_T440P -a (with VBOOT)

Change-Id: If1430ffd6115a0bc151cbe0632cda7fc5f6c26a6
Signed-off-by: Yu-Ping Wu <yupingso@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67540
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/cpu/intel/haswell/Kconfig

@@ -7,7 +7,6 @@ if CPU_INTEL_HASWELL
 config CPU_SPECIFIC_OPTIONS
 	def_bool y
 	select ARCH_X86
-	select BOOT_DEVICE_SPI_FLASH_NO_EARLY_WRITES
 	select MMX
 	select SSE2
 	select UDELAY_TSC