arm64: dts: fsd: fix drive strength macros as per FSD HW UM

Drive strength macros defined for FSD platform is not reflecting actual
names and values as per HW UM. FSD SoC pinctrl has following four levels
of drive-strength and their corresponding values:
Level-1 <-> 0
Level-2 <-> 1
Level-4 <-> 2
Level-6 <-> 3

The commit 684dac402f21 ("arm64: dts: fsd: Add initial pinctrl support")
used drive strength macros defined for Exynos4 SoC family. For some IPs
the macros values of Exynos4 matched and worked well, but Exynos4 SoC
family drive-strength (names and values) is not exactly matching with
FSD SoC.

Fix the drive strength macros to reflect actual names and values given
in FSD HW UM.

Fixes: 684dac402f21 ("arm64: dts: fsd: Add initial pinctrl support")
Signed-off-by: Padmanabhan Rajanbabu <p.rajanbabu@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20221013104024.50179-2-p.rajanbabu@samsung.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

arm64: dts: fsd: use local header for pinctrl register values

The DTS uses hardware register values directly in pin controller pin
configuration. These are not some IDs or other abstraction layer but
raw numbers used in the registers.

These numbers were previously put in the bindings header to avoid code
duplication and to provide some context meaning (name), but they do not
fit the purpose of bindings. It is also quite confusing to use
constants prefixed with Exynos for other SoC, because there is actually
nothing here in common, except the actual value.

Store the constants in a header next to DTS and use them instead of
bindings.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Chanho Park <chanho61.park@samsung.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220605160508.134075-7-krzysztof.kozlowski@linaro.org