Fix compilation error related explicit type cast error with IS_ERR_VALUE macro. Update CONFIG_MSM_BUS_SCALING to CONFIG_QCOM_BUS_SCALING. Replaced read_write_v_h macro with function. Change-Id: I748756e05f1e224e09f8131183d36cdbae628b74 Signed-off-by: Sachin Bhayare <sachin.bhayare@codeaurora.org>