unicore32 machine related files: add i2c bus drivers for pkunity-v3 soc

change from original version -- by advice of Jean Delvare
1. remove global variable i2c_reg, replaced by local variables
2. replace ENXIO with ENODEV when no platform resources
3. add adapter->nr assignment before i2c_add_numbered_adapter() call
4. add judgement for i2c_del_adapter() return value
5. release adapter when driver removed
6. add __devexit for puv3_i2c_remove() function
7. modify several names to more appropriated ones

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 113505a..cbfcf6f 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -523,6 +523,17 @@
 	  This driver can also be built as a module.  If so, the module
 	  will be called i2c-pnx.
 
+config I2C_PUV3
+	tristate "PKUnity v3 I2C bus support"
+	depends on UNICORE32 && ARCH_PUV3
+	select I2C_ALGOBIT
+	help
+	  This driver supports the I2C IP inside the PKUnity-v3 SoC.
+	  This I2C bus controller is under AMBA/AXI bus.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called i2c-puv3.
+
 config I2C_PXA
 	tristate "Intel PXA2XX I2C adapter"
 	depends on ARCH_PXA || ARCH_MMP