svga: disable srgb format related code from svga_blit()
svga: disable srgb format related code from svga_blit()

With latest mesa and latest piglit tests srgb<->linear conversion
is not required as per GL4.4 rules

See commit b662c70aeab6a92751514f30719c13a6de253b40.

Reviewed-by: Charmaine Lee <67ce69700661ea856134ddb10419a330e5f037d7@vmware.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler