memory: renesas-rpc-if: Fix PHYCNT.STRTIM setting

memory: renesas-rpc-if: Fix PHYCNT.STRTIM setting

According to the datasheets, the Strobe Timing Adjustment bit (STRTIM)
setting is different on R-Car SoCs, i.e.

R-Car M3 ES1.*  : STRTIM[2:0] is set to 0x6
other R-Car Gen3: STRTIM[2:0] is set to 0x7
other R-Car Gen4: STRTIM[3:0] is set to 0xf

To fix this issue, a DT match data was added to specify the setting
for special use cases.

Signed-off-by: Cong Dang <cong.dang.xn@renesas.com>
Signed-off-by: Hai Pham  <hai.pham.ud@renesas.com>
[wsa: rebased, restructured, added Gen4 support]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230419130234.44321-1-wsa+renesas@sang-engineering.com
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>