MX31ADS environment variable update, spi and rtc support

Update MX31ADS default environment to better match the flash layout and
the memory map, support SPI and RTC.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
diff --git a/board/mx31ads/mx31ads.c b/board/mx31ads/mx31ads.c
index 5a7d8c9..a75cc2d 100644
--- a/board/mx31ads/mx31ads.c
+++ b/board/mx31ads/mx31ads.c
@@ -57,6 +57,18 @@
 	mx31_gpio_mux(MUX_RTS1__UART1_RTS_B);
 	mx31_gpio_mux(MUX_RTS1__UART1_CTS_B);
 
+	/* SPI2 */
+	mx31_gpio_mux((MUX_CTL_FUNC << 8) | MUX_CTL_CSPI2_SS2);
+	mx31_gpio_mux((MUX_CTL_FUNC << 8) | MUX_CTL_CSPI2_SCLK);
+	mx31_gpio_mux((MUX_CTL_FUNC << 8) | MUX_CTL_CSPI2_SPI_RDY);
+	mx31_gpio_mux((MUX_CTL_FUNC << 8) | MUX_CTL_CSPI2_MOSI);
+	mx31_gpio_mux((MUX_CTL_FUNC << 8) | MUX_CTL_CSPI2_MISO);
+	mx31_gpio_mux((MUX_CTL_FUNC << 8) | MUX_CTL_CSPI2_SS0);
+	mx31_gpio_mux((MUX_CTL_FUNC << 8) | MUX_CTL_CSPI2_SS1);
+
+	/* start SPI2 clock */
+	__REG(CCM_CGR2) = __REG(CCM_CGR2) | (3 << 4);
+
 	/* PBC setup */
 	/* Enable UART transceivers also reset the Ethernet/external UART */
 	readw(CS4_BASE + 4);