drm/imagination: Numerous documentation fixes.

Some reported by Stephen Rothwell. The rest were found by running the
kernel-doc build script.
Some indentation fixes.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311241526.Y2WZeUau-lkp@intel.com/
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20231128173507.95119-1-donald.robson@imgtec.com

drm/imagination: Add GPU ID parsing and firmware loading

Read the GPU ID register at probe time and select the correct
features/quirks/enhancements. Use the GPU ID to form the firmware
file name and load the firmware.

The features/quirks/enhancements arrays are currently hardcoded in
the driver for the supported GPUs. We are looking at moving this
information to the firmware image.

Changes since v8:
- Corrected license identifiers

Changes since v7:
- Fix kerneldoc for pvr_device_info_set_enhancements()

Changes since v5:
- Add BRN 71242 to device info

Changes since v4:
- Retrieve device information from firmware header
- Pull forward firmware header parsing from FW infrastructure patch
- Use devm_add_action_or_reset to release firmware

Changes since v3:
- Use drm_dev_{enter,exit}

Co-developed-by: Frank Binns <frank.binns@imgtec.com>
Signed-off-by: Frank Binns <frank.binns@imgtec.com>
Co-developed-by: Matt Coster <matt.coster@imgtec.com>
Signed-off-by: Matt Coster <matt.coster@imgtec.com>
Co-developed-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Donald Robson <donald.robson@imgtec.com>
Signed-off-by: Sarah Walker <sarah.walker@imgtec.com>
Link: https://lore.kernel.org/r/1ff76f7a5b45c742279c78910f8491b8a5e7f6e6.1700668843.git.donald.robson@imgtec.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>