mmc: add the MMC_CLK_ENABLE/DISABLE macro in mmc.h

mmc_set_clock() function has the disable argument as bool type.
When mmc_set_clock is called, it might be passed to "true" or "false".
But it's too confusion whether clock is enabled or disabled with only
"true" and "false".
To prevent the confusion, replace to MMC_CLK_ENABLE/DISABLE macro from
true/false.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 01a02fb..29971a5 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -529,7 +529,7 @@
 	 * During a signal voltage level switch, the clock must be gated
 	 * for 5 ms according to the SD spec
 	 */
-	mmc_set_clock(mmc, mmc->clock, true);
+	mmc_set_clock(mmc, mmc->clock, MMC_CLK_DISABLE);
 
 	err = mmc_set_signal_voltage(mmc, signal_voltage);
 	if (err)
@@ -537,7 +537,7 @@
 
 	/* Keep clock gated for at least 10 ms, though spec only says 5 ms */
 	mdelay(10);
-	mmc_set_clock(mmc, mmc->clock, false);
+	mmc_set_clock(mmc, mmc->clock, MMC_CLK_ENABLE);
 
 	/*
 	 * Failure to switch is indicated by the card holding
@@ -1672,7 +1672,8 @@
 
 				/* configure the bus mode (host) */
 				mmc_select_mode(mmc, mwt->mode);
-				mmc_set_clock(mmc, mmc->tran_speed, false);
+				mmc_set_clock(mmc, mmc->tran_speed,
+						MMC_CLK_ENABLE);
 
 #ifdef MMC_SUPPORTS_TUNING
 				/* execute tuning if needed */
@@ -1697,7 +1698,8 @@
 error:
 				/* revert to a safer bus speed */
 				mmc_select_mode(mmc, SD_LEGACY);
-				mmc_set_clock(mmc, mmc->tran_speed, false);
+				mmc_set_clock(mmc, mmc->tran_speed,
+						MMC_CLK_ENABLE);
 			}
 		}
 	}
@@ -1858,7 +1860,7 @@
 		return -ENOTSUPP;
 	}
 
-	mmc_set_clock(mmc, mmc->legacy_speed, false);
+	mmc_set_clock(mmc, mmc->legacy_speed, MMC_CLK_ENABLE);
 
 	for_each_mmc_mode_by_pref(card_caps, mwt) {
 		for_each_supported_width(card_caps & mwt->widths,
@@ -1901,7 +1903,7 @@
 
 			/* configure the bus mode (host) */
 			mmc_select_mode(mmc, mwt->mode);
-			mmc_set_clock(mmc, mmc->tran_speed, false);
+			mmc_set_clock(mmc, mmc->tran_speed, MMC_CLK_ENABLE);
 #ifdef MMC_SUPPORTS_TUNING
 
 			/* execute tuning if needed */
@@ -2426,7 +2428,7 @@
 
 	mmc_select_mode(mmc, MMC_LEGACY);
 	mmc_set_bus_width(mmc, 1);
-	mmc_set_clock(mmc, 0, false);
+	mmc_set_clock(mmc, 0, MMC_CLK_ENABLE);
 }
 
 static int mmc_power_on(struct mmc *mmc)
@@ -2446,7 +2448,7 @@
 
 static int mmc_power_off(struct mmc *mmc)
 {
-	mmc_set_clock(mmc, 0, true);
+	mmc_set_clock(mmc, 0, MMC_CLK_DISABLE);
 #if CONFIG_IS_ENABLED(DM_MMC) && CONFIG_IS_ENABLED(DM_REGULATOR)
 	if (mmc->vmmc_supply) {
 		int ret = regulator_set_enable(mmc->vmmc_supply, false);