Old Exynos SoCs have both Product ID and Revision ID in one single
register, while new SoCs tend to have two separate registers for those
IDs. Implement handling of both cases by passing Revision ID register
offsets in driver data.

Previously existing macros for Exynos4210 (removed in this patch) were
incorrect:

    #define EXYNOS_SUBREV_MASK         (0xf << 4)
    #define EXYNOS_MAINREV_MASK        (0xf << 0)

Actual format of PRO_ID register in Exynos4210 (offset 0x0):

    [31:12] Product ID
      [9:8] Package information
      [7:4] Main Revision Number
      [3:0] Sub Revision Number

This patch doesn't change the behavior on existing platforms, so
'/sys/devices/soc0/revision' will show the same string as before.
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Tested-by: Henrik Grimler <henrik@grimler.se>
Link: https://lore.kernel.org/r/20211014133508.1210-1-semen.protsenko@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>