ARM: tegra: drop CONFIG_DISABLE_SDMMC1_EARLY

This was a temporary workaround for the Tegra210 Jetson Nano board. It is
not used by any device anymore, so let's remove it.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>

arch/arm/mach-tegra/board2.c

@@ -227,31 +227,6 @@ int board_early_init_f(void)
 		arch_timer_init();
 #endif
 
-#if defined(CONFIG_DISABLE_SDMMC1_EARLY)
-	/*
-	 * Turn off (reset/disable) SDMMC1 on Nano here, before GPIO INIT.
-	 * We do this because earlier bootloaders have enabled power to
-	 * SDMMC1 on Nano, and toggling power-gpio (PZ3) in pinmux_init()
-	 * results in power being back-driven into the SD-card and SDMMC1
-	 * HW, which is 'bad' as per the HW team.
-	 *
-	 * From the HW team: "LDO2 from the PMIC has already been set to 3.3v in
-	 * nvtboot/CBoot on Nano (for SD-card boot). So when U-Boot's GPIO_INIT
-	 * table sets PZ3 to OUT0 as per the pinmux spreadsheet, it turns off
-	 * the loadswitch. When PZ3 is 0 and not driving, essentially the SDCard
-	 * voltage turns off. Since the SDCard voltage is no longer there, the
-	 * SDMMC CLK/DAT lines are backdriving into what essentially is a
-	 * powered-off SDCard, that's why the voltage drops from 3.3V to ~1.6V"
-	 *
-	 * Note that this can probably be removed when we change over to storing
-	 * all BL components on QSPI on Nano, and U-Boot then becomes the first
-	 * one to turn on SDMMC1 power. Another fix would be to have CBoot
-	 * disable power/gate SDMMC1 off before handing off to U-Boot/kernel.
-	 */
-	reset_set_enable(PERIPH_ID_SDMMC1, 1);
-	clock_set_enable(PERIPH_ID_SDMMC1, 0);
-#endif	/* CONFIG_DISABLE_SDMMC1_EARLY */
-
 	pinmux_init();
 	board_init_uart_f();