Merge remote-tracking branch 'remotes/kraxel/tags/vga-20200701-pull-request' into...

vga: bugfixes for ati and sm501, vgabios cleanup.

# gpg: Signature made Wed 01 Jul 2020 16:03:48 BST
# gpg:                using RSA key 4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>" [full]
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>" [full]
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>" [full]
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/vga-20200701-pull-request:
  configure: vgabios cleanups
  ati-vga: Add dummy MEM_SDRAM_MODE_REG
  ati-vga: Do not assert on error
  ati-vga: Support unaligned access to hardware cursor registers
  sm501: Fix and optimize overlap check
  sm501: Convert debug printfs to traces
  sm501: Do not allow guest to set invalid format
  sm501: Use stn_he_p/ldn_he_p instead of switch/case
  sm501: Optimise 1 pixel 2d ops
  sm501: Introduce variable for commonly used value for better readability
  sm501: Ignore no-op blits
  sm501: Drop unneded variable
  sm501: Fix bounds checks

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>