driver/mxc_i2c: Move static data structure to global_data

This driver needs a data structure in SRAM before SDRAM is available.
This is not alway the case using .data section. Moving this data
structure to global_data guarantees it is writable.

Signed-off-by: York Sun <yorksun@freescale.com>
CC: Troy Kisky <troy.kisky@boundarydevices.com>

include/asm-generic/global_data.h

@@ -79,6 +79,9 @@ typedef struct global_data {
 #endif
 #if defined(CONFIG_SYS_I2C)
 	int		cur_i2c_bus;	/* current used i2c bus */
+#endif
+#ifdef CONFIG_SYS_I2C_MXC
+	void *srdata[10];
 #endif
 	unsigned long timebase_h;
 	unsigned long timebase_l;