dw_dmac: fix a regression in dwc_prep_dma_memcpy
dw_dmac: fix a regression in dwc_prep_dma_memcpy

Sometimes memory-to-memory test is failed, that's why we need to choose minimum
data portion between source and destination limits together.

Signed-off-by: Andy Shevchenko <74f0c009df510614346aa771cd21959b78cdb413@linux.intel.com>
Signed-off-by: Vinod Koul <5cf69c63beb17bf38d63aa0e923ee8256af0e205@linux.intel.com>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs