bus: mhi: pci_generic: Add mru_default for Quectel EM1xx series

For default mechanism, the driver uses default MRU 3500 if mru_default
is not initialized. The Qualcomm configured the MRU size to 32768 in the
WWAN device FW. So, we align the driver setting with Qualcomm FW setting.

Link: https://lore.kernel.org/r/MEYP282MB2374EE345DADDB591AFDA6AFFD2E9@MEYP282MB2374.AUSP282.PROD.OUTLOOK.COM
Fixes: ac4bf60b ("bus: mhi: pci_generic: Introduce quectel EM1XXGR-L support")
Cc: stable@vger.kernel.org
Reviewed-by: NManivannan Sadhasivam <mani@kernel.org>
Signed-off-by: NYonglin Tan <yonglin.tan@outlook.com>
Signed-off-by: NManivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/20220301160308.107452-2-manivannan.sadhasivam@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mhi/pci_generic.c

@@ -327,6 +327,7 @@ static const struct mhi_pci_dev_info mhi_quectel_em1xx_info = {
 	.config = &modem_quectel_em1xx_config,
 	.bar_num = MHI_PCI_DEFAULT_BAR_NUM,
 	.dma_data_width = 32,
+	.mru_default = 32768,
 	.sideband_wake = true,
 };