drm/vmwgfx: Revert "drm/vmwgfx: Replace numeric parameter like 0444 with macro"

This reverts commit 2d8e60e8 ("drm/vmwgfx: Replace numeric
parameter like 0444 with macro")

The commit belongs to the series of 1285 patches sent to LKML on
2016-08-02, it changes the representation of file permissions from the
octal value "0600" to "S_IRUSR | S_IWUSR".

The general consensus was that the changes does not increase
readability, quite the opposite; 0600 is easier to parse mentally than
S_IRUSR | S_IWUSR.

It also causes argument inconsistency, due to commit 04319d89
("drm/vmwgfx: Add an option to change assumed FB bpp") that added
another call to module_param_named() where the permissions are written
as 0600.

Signed-off-by: Øyvind A. Holm <sunny@sunbase.org>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>