usb: gadget: mtp: increase MTP buffers

usb: gadget: mtp: increase MTP buffers

Increase the buffer size to 32KB to improve MTP throughput and
keep the first packet size to 16KB for files greater than 4GB

Bug 1168348
Bug 1216779

Change-Id: I31c78223870b788a67d628005026f6e3608df04f
Signed-off-by: Rakesh Bodla <rbodla@nvidia.com>
Reviewed-on: http://git-master/r/207589
(cherry picked from commit b64b3f926455e9cfdff90291525f3d5264b97dd4)
Reviewed-on: http://git-master/r/229671
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Venkat Moganty <vmoganty@nvidia.com>