gpu: ion: include msm-specific ion header

All msm_ion clients need to use <linux/msm_ion.h> instead of
<linux/ion.h>

Change-Id: I4f999e301d147ec3242a33ee75b10b6501d42a70
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
gpu: ion: move msm-specific ioctls to custom_ioctl

To avoid collisions with future ioctls that may be added to ion,
msm-specific ioctls should use the `custom_ioctl' interface provided
by struct ion_device, as originally intended.

Change-Id: I68d32b81c7691fd3f54f38acfdc17fee2573bc44
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
ion: remove ion_validate_buffer_flag

ion_validate_buffer_flag is no longer needed since its only callers
are moving to a new format for buffer flags.

Change-Id: I90f23123681eaefb40b530aec5eaf596770acf18
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
gpu: ion: Add support for device tree.

Add device tree parsing to common msm ion code
to allow new targets to specify ION heap configuration
in device tree.

Document the device tree bindings for ION.

Change-Id: I40b7f4b1fbb3ca4ad1d6dc06a33b647f6af1d669
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
gpu: ion: IOCTL return success when error occurs

ION_IOC_IMPORT may return success when an error occurs. Add correct
error handling to ION_IOC_IMPORT.

Change-Id: I5aa552fae0e11b623fba4eed65b5c3c9c8b21597
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
[mitchelh@codeaurora.org: re-adding patch that fell out]
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>