[nrf fromlist] soc: nordic: nrf54l: remove normal voltage mode

Normal voltage mode is no longer supported by MDK 8.67.0.

Upstream PR: zephyrproject-rtos/zephyr#78643

Signed-off-by: Nikodem Kastelik <[email protected]>
(cherry picked from commit 243111c25d712a4fb426a6ddd86ee7814a713131)

Author: nika-nordic

soc/nordic/nrf54l/Kconfig

@@ -87,9 +87,6 @@ config SOC_NRF_FORCE_CONSTLAT
 	  of base resources on while in sleep. The advantage of having a constant
 	  and predictable latency will be at the cost of having increased power consumption.
 
-config SOC_NRF54L_NORMAL_VOLTAGE_MODE
-	bool "NRF54L Normal Voltage Mode."
-
 if NRF_GRTC_TIMER
 
 config ELV_GRTC_LFXO_ALLOWED

soc/nordic/nrf54l/soc.c

@@ -157,10 +157,6 @@ static inline void power_and_clock_configuration(void)
 	nrf_regulators_vreg_enable_set(NRF_REGULATORS, NRF_REGULATORS_VREG_MAIN, true);
 #endif
 
-	if (IS_ENABLED(CONFIG_SOC_NRF54L_NORMAL_VOLTAGE_MODE)) {
-		nrf_regulators_vreg_enable_set(NRF_REGULATORS, NRF_REGULATORS_VREG_MEDIUM, false);
-	}
-
 #if defined(CONFIG_ELV_GRTC_LFXO_ALLOWED)
 	nrf_regulators_elv_mode_allow_set(NRF_REGULATORS, NRF_REGULATORS_ELV_ELVGRTCLFXO_MASK);
 #endif /* CONFIG_ELV_GRTC_LFXO_ALLOWED */