Revert "spi: bcm-qspi: shut up warning about cfi header inclusion"

This reverts commit c30e6636.

Florian writes:
	Sorry for noticing so late, but this appears to be bogus, there
	is no MTD_NORFLASH symbol being defined in 4.9, in fact I can't
	find this Kconfig symbol in any kernel version, so this
	effectively results in the driver no longer being selectable, so
	this sure does silence the warning.

It's not good to just disable a whole driver :(

So let's revert the patch for now, Arnd can work on a better build
fix...

Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>