hw/i2c/versatile_i2c: Add SCL/SDA definitions

Use self-explicit definitions instead of magic values.
Signed-off-by: NPhilippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20200617072539.32686-4-f4bug@amsat.org
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>

hw/i2c/versatile_i2c.c

@@ -45,6 +45,9 @@ REG32(CONTROL_GET, 0)
 REG32(CONTROL_SET, 0)
 REG32(CONTROL_CLR, 4)
 
+#define SCL BIT(0)
+#define SDA BIT(1)
+
 static uint64_t versatile_i2c_read(void *opaque, hwaddr offset,
                                    unsigned size)
 {
@@ -76,8 +79,8 @@ static void versatile_i2c_write(void *opaque, hwaddr offset,
         qemu_log_mask(LOG_GUEST_ERROR,
                       "%s: Bad offset 0x%x\n", __func__, (int)offset);
     }
-    bitbang_i2c_set(&s->bitbang, BITBANG_I2C_SCL, (s->out & 1) != 0);
-    s->in = bitbang_i2c_set(&s->bitbang, BITBANG_I2C_SDA, (s->out & 2) != 0);
+    bitbang_i2c_set(&s->bitbang, BITBANG_I2C_SCL, (s->out & SCL) != 0);
+    s->in = bitbang_i2c_set(&s->bitbang, BITBANG_I2C_SDA, (s->out & SDA) != 0);
 }
 
 static const MemoryRegionOps versatile_i2c_ops = {