Remove SK_FREETYPE_HAS_MM.
Remove SK_FREETYPE_HAS_MM.

The SK_FREETYPE_HAS_MM define was added to delay the changes to
support GX variation fonts on platforms which did not compile ftmm.c
into their FreeType build. Now that all builds should have this file
the define can be removed.

Committed: https://skia.googlesource.com/skia/+/4f61fee53af956a8beb4c56fa6479cb6b1aa5159

Review URL: https://codereview.chromium.org/1143133006

noselhq/skia,Hikari-no-Tenshi/android_external_skia,vanish87/skia,Jichao/skia,rubenvb/skia,HalCanary/skia-hc,google/skia,qrealka/skia-hc,tmpvar/skia.cc,noselhq/skia,pcwalton/skia,Hikari-no-Tenshi/android_external_skia,HalCanary/skia-hc,Hikari-no-Tenshi/android_external_skia,Jichao/skia,rubenvb/skia,rubenvb/skia,aosp-mirror/platform_external_skia,rubenvb/skia,todotodoo/skia,HalCanary/skia-hc,tmpvar/skia.cc,tmpvar/skia.cc,ominux/skia,Jichao/skia,noselhq/skia,todotodoo/skia,google/skia,rubenvb/skia,vanish87/skia,shahrzadmn/skia,aosp-mirror/platform_external_skia,Jichao/skia,nvoron23/skia,vanish87/skia,qrealka/skia-hc,ominux/skia,Hikari-no-Tenshi/android_external_skia,ominux/skia,google/skia,qrealka/skia-hc,google/skia,pcwalton/skia,nvoron23/skia,Jichao/skia,nvoron23/skia,Jichao/skia,rubenvb/skia,shahrzadmn/skia,aosp-mirror/platform_external_skia,shahrzadmn/skia,nvoron23/skia,Hikari-no-Tenshi/android_external_skia,noselhq/skia,tmpvar/skia.cc,todotodoo/skia,HalCanary/skia-hc,ominux/skia,HalCanary/skia-hc,rubenvb/skia,tmpvar/skia.cc,aosp-mirror/platform_external_skia,nvoron23/skia,Jichao/skia,rubenvb/skia,HalCanary/skia-hc,Jichao/skia,noselhq/skia,vanish87/skia,vanish87/skia,noselhq/skia,rubenvb/skia,todotodoo/skia,shahrzadmn/skia,noselhq/skia,qrealka/skia-hc,google/skia,shahrzadmn/skia,ominux/skia,todotodoo/skia,pcwalton/skia,vanish87/skia,google/skia,google/skia,rubenvb/skia,nvoron23/skia,aosp-mirror/platform_external_skia,pcwalton/skia,aosp-mirror/platform_external_skia,qrealka/skia-hc,qrealka/skia-hc,HalCanary/skia-hc,pcwalton/skia,google/skia,shahrzadmn/skia,google/skia,aosp-mirror/platform_external_skia,noselhq/skia,noselhq/skia,aosp-mirror/platform_external_skia,Hikari-no-Tenshi/android_external_skia,Jichao/skia,Hikari-no-Tenshi/android_external_skia,tmpvar/skia.cc,vanish87/skia,todotodoo/skia,qrealka/skia-hc,shahrzadmn/skia,shahrzadmn/skia,tmpvar/skia.cc,HalCanary/skia-hc,ominux/skia,nvoron23/skia,pcwalton/skia,pcwalton/skia,shahrzadmn/skia,todotodoo/skia,vanish87/skia,HalCanary/skia-hc,nvoron23/skia,Hikari-no-Tenshi/android_external_skia,aosp-mirror/platform_external_skia,todotodoo/skia,pcwalton/skia,ominux/skia,pcwalton/skia,todotodoo/skia,qrealka/skia-hc,vanish87/skia,tmpvar/skia.cc,ominux/skia,google/skia,aosp-mirror/platform_external_skia,HalCanary/skia-hc,tmpvar/skia.cc,nvoron23/skia,ominux/skia