main: Change u_mmAllocMem align2 from bytes (old API) to bits (new API)
The main and Gallium implementations were recently merged, and the align2 parameter in the Gallium one is in bits. execmem.c expected bytes still. This led to every call here asserting.
Fixes: b6fd679a("mesa/main/util: moving gallium u_mm to util, remove main/mm")
Reviewed-by: Alejandro Piñeiro apinheiro@igalia.com