i2c: qup: New bus driver for the Qualcomm QUP I2C controller

This bus driver supports the QUP i2c hardware controller in the Qualcomm SOCs.
The Qualcomm Universal Peripheral Engine (QUP) is a general purpose data path
engine with input/output FIFOs and an embedded i2c mini-core. The driver
supports FIFO mode (for low bandwidth applications) and block mode (interrupt
generated for each block-size data transfer).

Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@sonymobile.com>
Reviewed-by: Andy Gross <agross@codeaurora.org>
Tested-by: Philip Elcan <pelcan@codeaurora.org>
[wsa: removed needless IS_ERR_VALUE]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>