soc: arm: Fix cmake linker.ld warning for arduino_uno_r4_minima

Fix cmake depreciation warning on pre-defined linker.id
(soc/arm/renesas_ra/ra4m1/linker.ld) used for arduino_uno_r4_minima.

Signed-off-by: Dmitrii Golovanov <dmitrii.golovanov@intel.com>