LDEVOBJ_bBuildDevmodeList() only queries the available display modes, without
choosing the one to use on the graphic device, and without immediately
creating a PDEV.
Replace first part of EngpPopulateDeviceModeList() function by a call
to this new function LDEVOBJ_bBuildDevmodeList().
Keep second part of EngpPopulateDeviceModeList() function, which
chooses the default display mode.
- implement LDEVOBJ_ulGetDriverModes (which get modes from a not yet loaded driver),
and use it in EngpPopulateDeviceModeList
- remove now useless LDEVOBJ_pdmiGetModes (replaced by LDEVOBJ_ulGetDriverModes)
- Change INIT_FUNCTION and INIT_SECTION to CODE_SEG("INIT") and DATA_SEG("INIT") respectively
- Remove INIT_FUNCTION from function prototypes
- Remove alloc_text pragma calls as they are not needed anymore
