gpu: nvgpu: Add new subdirs to common/mm

Add two new sub-directories under MM: gmmu and allocators.

The allocators directory is for all the allocator code we have.
There's a fair amount and as such could be considered a component
with a bunch of sub-units.

The new GMMU directory will contain the GMMU component (which used to
be a single unit). The new GMMU component is comprised of the
page_table and pd_cache units. Also when we migrate the chip specific
GMMU code out of mm_gk20a.c and mm_gp10b.c it will be placed in this
new GMMU directory.

JIRA NVGPU-1390

Change-Id: I7aa47ea2a32612b7d69972671fccb72770e1ae09
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1944385
Reviewed-by: Nicolas Benech <nbenech@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/Makefile

@@ -210,13 +210,13 @@ nvgpu-$(CONFIG_NVGPU_SUPPORT_CDE) += \
 endif
 
 nvgpu-y += \
-	common/mm/nvgpu_allocator.o \
-	common/mm/bitmap_allocator.o \
-	common/mm/buddy_allocator.o \
-	common/mm/page_allocator.o \
-	common/mm/lockless_allocator.o \
-	common/mm/gmmu.o \
-	common/mm/pd_cache.o \
+	common/mm/allocators/nvgpu_allocator.o \
+	common/mm/allocators/bitmap_allocator.o \
+	common/mm/allocators/buddy_allocator.o \
+	common/mm/allocators/page_allocator.o \
+	common/mm/allocators/lockless_allocator.o \
+	common/mm/gmmu/page_table.o \
+	common/mm/gmmu/pd_cache.o \
 	common/mm/vm.o \
 	common/mm/vm_area.o \
 	common/mm/nvgpu_mem.o \

drivers/gpu/nvgpu/Makefile.sources

@@ -46,13 +46,13 @@ srcs :=	os/posix/nvgpu.c \
 	os/posix/stubs.c \
 	os/posix/posix-fault-injection.c \
 	os/posix/gk20a.c \
-	common/mm/nvgpu_allocator.c \
-	common/mm/bitmap_allocator.c \
-	common/mm/buddy_allocator.c \
-	common/mm/page_allocator.c \
-	common/mm/lockless_allocator.c \
-	common/mm/gmmu.c \
-	common/mm/pd_cache.c \
+	common/mm/allocators/nvgpu_allocator.c \
+	common/mm/allocators/bitmap_allocator.c \
+	common/mm/allocators/buddy_allocator.c \
+	common/mm/allocators/page_allocator.c \
+	common/mm/allocators/lockless_allocator.c \
+	common/mm/gmmu/page_table.c \
+	common/mm/gmmu/pd_cache.c \
 	common/mm/vm.c \
 	common/mm/vm_area.c \
 	common/mm/nvgpu_mem.c \