[nrf fromlist] soc: nordic: nrf54l: remove configuration of DCDC regulator

Since nrfx 3.9 integration, configuration is executed
in MDK SystemInit().

Upstream PR #: 82268

Signed-off-by: Nikodem Kastelik <[email protected]>
(cherry picked from commit 8101d21)

Author: nika-nordic

soc/nordic/nrf54l/soc.c

@@ -154,11 +154,6 @@ static inline void power_and_clock_configuration(void)
 	}
 
 #if (DT_PROP(DT_NODELABEL(vregmain), regulator_initial_mode) == NRF5X_REG_MODE_DCDC)
-#if defined(__CORTEX_M) && !defined(NRF_TRUSTZONE_NONSECURE) && defined(__ARM_FEATURE_CMSE)
-	if (*(uint32_t volatile *)0x00FFC334 <= 0x180A1D00) {
-		*(uint32_t volatile *)0x50120640 = 0x1EA9E040;
-	}
-#endif
 	nrf_regulators_vreg_enable_set(NRF_REGULATORS, NRF_REGULATORS_VREG_MAIN, true);
 #endif