drm/xe/eustall: Add WA 14027054324 support for graphics IP 35.11

WA 14027054324 is implemented in the firmware and is applied before
EU stall sampling and reverted after EU stall sampling. The driver
needs to notify the firmware whenever EU stall sampling is being
enabled/disabled so that the firmware takes the necessary action.
The driver uses a scratch pad register to communicate with the firmware.

Before enabling EU stall sampling, write 0x20 to the SWF scratch pad
register to request the firmware to apply the workaround. The firmware
applies the workaround and sets the scratch pad register to 0x60
as an ACK.

Before disabling EU stall sampling, write 0x40 to the SWF scratch pad
register to request the firmware to revert the workaround. The firmware
reverts the workaround and sets the scratch pad register to 0 as an ACK.

The firmware is expected to take about 1 ms to apply/revert the
workaround. 10 ms timeout is used in the driver while waiting for an
ack from the firmware to have adequate grace period.

Bspec update for the SWF scratch pad register is still pending, but has
been confirmed offline with the firmware team.

Bspec: 53188
Signed-off-by: Harish Chegondi <harish.chegondi@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patch.msgid.link/16b6b972691943daddebad6e7b93b9d73add5249.1784745545.git.harish.chegondi@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>

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