net: pcs: Kconfig: Fix unmet dependency warning

net: pcs: Kconfig: Fix unmet dependency warning

Fix the Kconfig dependencies for PCS_RZN1_MIIC to avoid the unmet direct
dependency warning when enabling DWMAC_RENESAS_GBETH. The PCS driver is
used on multiple Renesas SoCs including RZ/N1, RZ/N2H and RZ/T2H, but the
existing condition only allowed ARCH_RZN1, ARCH_R9A09G077, or
ARCH_R9A09G087. This conflicted with the GBETH/GMAC driver which selects
PCS_RZN1_MIIC under ARCH_RENESAS.

Update the dependency to ARCH_RENESAS || COMPILE_TEST so that the PCS
driver is available on all Renesas platforms.

Fixes: 08f89e42121d ("net: pcs: rzn1-miic: Add RZ/T2H MIIC support")
Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/all/aMlgg_QpJOEDGcEA@monster/
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20250916162335.3339558-1-prabhakar.mahadev-lad.rj@bp.renesas.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>