SPI: mxc_spi: replace fixed offsets with structures

This patch cleans driver code replacing all accesses
to registers with fixed offsets with a corresponding
structure.

Signed-off-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/include/asm/arch-mx35/imx-regs.h b/arch/arm/include/asm/arch-mx35/imx-regs.h
index 7978444..e741fb0 100644
--- a/arch/arm/include/asm/arch-mx35/imx-regs.h
+++ b/arch/arm/include/asm/arch-mx35/imx-regs.h
@@ -265,6 +265,18 @@
 	u32 counter;	/* counter */
 };
 
+/* CSPI registers */
+struct cspi_regs {
+	u32 rxdata;
+	u32 txdata;
+	u32 ctrl;
+	u32 intr;
+	u32 dma;
+	u32 stat;
+	u32 period;
+	u32 test;
+};
+
 /* Watchdog Timer (WDOG) registers */
 struct wdog_regs {
 	u16 wcr;	/* Control */