mmc: meson-gx: move arch header to local header

Move the asm/arch-meson/sd_emmc.h to a local meson_gx_mmc.h,
remove the useless if/then and fix the meson_gx_mmc.c include.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/drivers/mmc/meson_gx_mmc.c b/drivers/mmc/meson_gx_mmc.c
index 719dd1e..eedebb3 100644
--- a/drivers/mmc/meson_gx_mmc.c
+++ b/drivers/mmc/meson_gx_mmc.c
@@ -13,9 +13,9 @@
 #include <mmc.h>
 #include <asm/io.h>
 #include <asm/gpio.h>
-#include <asm/arch/sd_emmc.h>
 #include <linux/delay.h>
 #include <linux/log2.h>
+#include "meson_gx_mmc.h"
 
 static inline void *get_regbase(const struct mmc *mmc)
 {