stm32mp1: use unsigned values for SDMMC defines

Correct SDMMC macros to define unsigned values as expected by the
driver implementation.

Change-Id: Ib009f3df2cf26a9759d129eb571a27b2564770ce
Signed-off-by: Yann Gautier <yann.gautier@st.com>

plat/st/stm32mp1/stm32mp1_def.h

@@ -223,11 +223,11 @@ enum ddr_type {
 #define STM32MP_SDMMC2_BASE		U(0x58007000)
 #define STM32MP_SDMMC3_BASE		U(0x48004000)
 
-#define STM32MP_MMC_INIT_FREQ			400000		/*400 KHz*/
-#define STM32MP_SD_NORMAL_SPEED_MAX_FREQ	25000000	/*25 MHz*/
-#define STM32MP_SD_HIGH_SPEED_MAX_FREQ		50000000	/*50 MHz*/
-#define STM32MP_EMMC_NORMAL_SPEED_MAX_FREQ	26000000	/*26 MHz*/
-#define STM32MP_EMMC_HIGH_SPEED_MAX_FREQ	52000000	/*52 MHz*/
+#define STM32MP_MMC_INIT_FREQ			U(400000)	/*400 KHz*/
+#define STM32MP_SD_NORMAL_SPEED_MAX_FREQ	U(25000000)	/*25 MHz*/
+#define STM32MP_SD_HIGH_SPEED_MAX_FREQ		U(50000000)	/*50 MHz*/
+#define STM32MP_EMMC_NORMAL_SPEED_MAX_FREQ	U(26000000)	/*26 MHz*/
+#define STM32MP_EMMC_HIGH_SPEED_MAX_FREQ	U(52000000)	/*52 MHz*/
 
 /*******************************************************************************
  * STM32MP1 BSEC / OTP