mxs: Rename CONFIG_SPL_MX28_PSWITCH_WAIT to CONFIG_SPL_MXS_PSWITCH_WAIT

The power switch option is compatible with i.MX23 and i.MX28 so the
configration option needs to reflect it. We choose
'CONFIG_SPL_MXS_PSWITCH_WAIT' for the option name.

Series-changes: 2
- Rewrite short description as per Marek's request

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mx23: Enable tRAS lockout (24 bit of HW_DRAM_CTL08) as in imx-bootlets

This enables the 'Fast Auto Pre-Charge' found in the memory chip.

Series-changes: 2
- Improve commit message

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mx23evk: Adjust DRAM control register to use full 128MB of RAM

Series-to: uboot
Series-version: 2

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
led: Use STATUS_LED_ON and STATUS_LED_OFF when calling __led_set

This fixes the gpio_led driver which needs to compare againt a
STATUS_LED_ON to enable a led.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
mx23_olinuxino: Add support for status LED

This allow user to know if the bootloader is running, even without a
serial console.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>