kernel: bump 5.4 to 5.4.75

Manually rebased patches:
  bcm27xx:
    patches-5.4/950-0267-xhci-add-quirk-for-host-controllers-that-don-t-updat.patch
  bcm53xx:
    patches-5.4/180-usb-xhci-add-support-for-performing-fake-doorbell.patch
  layerscape:
    patches-5.4/802-can-0025-can-flexcan-add-LPSR-mode-support-for-i.MX7D.patch
    patches-5.4/808-i2c-0002-MLK-10893-i2c-imx-add-irqf_no_suspend.patch
    patches-5.4/820-usb-0016-MLK-16735-usb-host-add-XHCI_CDNS_HOST-flag.patch

Removed since could be reverse-applied by quilt:
  mediatek:
    patches-5.4/0700-arm-dts-mt7623-add-missing-pause-for-switchport.patch

All modifications made by update_kernel.sh

Build system: x86_64
Build-tested: ipq806x/R7800, ath79/generic, bcm27xx/bcm2711, x86_64
Run-tested: ipq806x/R7800, x86_64

No dmesg regressions, everything functional

Signed-off-by: John Audia <graysky@archlinux.us>
Tested-by: Curtis Deptuck <curtdept@me.com> [x86_64]

Rebase of 802-can-0025-can-flexcan-add-LPSR-mode-support-for-i.MX7D.patch
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: Kevin Darbyshire-Bryant <kevin@darbyshire-bryant.me.uk>

target/linux/mediatek/patches-5.4/0700-arm-dts-mt7623-add-missing-pause-for-switchport.patch

@@ -1,23 +0,0 @@
-From: Frank Wunderlich <frank-w@public-files.de>
-Date: Mon,  7 Sep 2020 09:05:17 +0200
-
-port6 of mt7530 switch (= cpu port 0) on bananapi-r2 misses pause option
-which causes rx drops on running iperf.
-
-Cc: stable@vger.kernel.org
-Fixes: f4ff257cd160 ("arm: dts: mt7623: add support for Bananapi R2 (BPI-R2) board")
-Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
----
- arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts | 1 +
- 1 file changed, 1 insertion(+)
-
---- a/arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts
-+++ b/arch/arm/boot/dts/mt7623n-bananapi-bpi-r2.dts
-@@ -193,6 +193,7 @@
- 					fixed-link {
- 						speed = <1000>;
- 						full-duplex;
-+						pause;
- 					};
- 				};
- 			};