fix(nxp-mmc): fix clk_rate and bus_width type

Both 'clk_rate' and bus_width members of the 'struct imx_usdhc_params'
are defined as integers, while their usages are unsigned int.
Therefore, change the type to unsigned int. This also helps to avoid
MISRA C-2012 Rule 10.3 violations when unsigned values are assigned to
signed variables.

Change-Id: If52e15a164732b68286f5303c4acbeb4ff993081
Signed-off-by: Ghennadi Procopciuc <ghennadi.procopciuc@nxp.com>
diff --git a/drivers/imx/usdhc/imx_usdhc.h b/drivers/imx/usdhc/imx_usdhc.h
index 49cd481..6ac4b0e 100644
--- a/drivers/imx/usdhc/imx_usdhc.h
+++ b/drivers/imx/usdhc/imx_usdhc.h
@@ -12,8 +12,8 @@
 
 typedef struct imx_usdhc_params {
 	uintptr_t	reg_base;
-	int		clk_rate;
-	int		bus_width;
+	unsigned int	clk_rate;
+	unsigned int	bus_width;
 	unsigned int	flags;
 } imx_usdhc_params_t;