revert wallpapermaxwidth overlay hack

deprecated due to commit 289c273ec49462c7bfdbf6238e9016936da7307c:
https://android-review.googlesource.com/#/c/95111/

wallpaper: limit wallpaper width to sys.max_texture_size

Image wallpapers are created ~1.5x screen size.  On some devices this
may exceed the maximum supported texture size, which will either fail
allocation or fail to composite.

Bug 991597

Change-Id: Iea5f6b496db7b3b50e44a4d5f62521597487d031