designware_i2c: remove inclusion of <asm/arch/hardware.h>

As soon as all boards have their CONFIG_SYS_I2C_BASE defined in
configuration files instead of "asm/arch/hardware.h" it's safe to remove
the inclusion in question and make driver platform-independent.

Cc: Tom Rini <trini@ti.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Stefan Roese <sr@denx.de>
Cc: Vipin Kumar <vipin.kumar@st.com>
Cc: Armando Visconti <armando.visconti@st.com>

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
diff --git a/drivers/i2c/designware_i2c.c b/drivers/i2c/designware_i2c.c
index deea4f8..c891ebd 100644
--- a/drivers/i2c/designware_i2c.c
+++ b/drivers/i2c/designware_i2c.c
@@ -7,7 +7,6 @@
 
 #include <common.h>
 #include <asm/io.h>
-#include <asm/arch/hardware.h>
 #include "designware_i2c.h"
 
 #ifdef CONFIG_I2C_MULTI_BUS