kernel: Bump to 4.9.76

kernel: overlays: Add uart0 overlay to change pin usage
kernel: overlays: Fix resetgpio and ledgpio for hy28a/b
See: raspberrypi/linux#2344

firmware: i2c_gpio: Preserve errors when asserts are suppressed

Author: popcornmix

boot/fixup.dat

@@ -1643,8 +1643,19 @@ Params: speed                   Display SPI bus speed
                 dtoverlay=tinylcd35,touch,touchgpio=3
 
 
+Name:   uart0
+Info:   Change the pin usage of uart0
+Load:   dtoverlay=uart0,<param>=<val>
+Params: txd0_pin                GPIO pin for TXD0 (14, 32 or 36 - default 14)
+
+        rxd0_pin                GPIO pin for RXD0 (15, 33 or 37 - default 15)
+
+        pin_func                Alternative pin function - 4(Alt0) for 14&15,
+                                7(Alt3) for 32&33, 6(Alt2) for 36&37
+
+
 Name:   uart1
-Info:   Enable uart1 in place of uart0
+Info:   Change the pin usage of uart1
 Load:   dtoverlay=uart1,<param>=<val>
 Params: txd1_pin                GPIO pin for TXD1 (14, 32 or 40 - default 14)