ARM: ixp4xx: Remove feature bit accessors

We switched users of the accessors over to using syscon to inspect
the bits, or removed the need for checking them. Delete these
accessors.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220211223238.648934-11-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

soc: ixp4xx: Add features from regmap helper

If we want to read the CFG2 register on the expansion bus and
apply the inversion and check for some hardcoded versions this
helper comes in handy.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220211223238.648934-7-linus.walleij@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

soc: ixp4xx: move cpu detection to linux/soc/ixp4xx/cpu.h

Generic drivers are unable to use the feature macros from mach/cpu.h
or the feature bits from mach/hardware.h, so move these into a global
header file along with some dummy helpers that list these features as
disabled elsewhere.

Cc: David S. Miller <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: netdev@vger.kernel.org
Cc: Zoltan HERPAI <wigyori@uid0.hu>
Cc: Raylynn Knight <rayknight@me.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>