IS31FL3741 driver fixup (qmk#10519)

* Fix issue with data transfer of CS1_SW7 to CS18_SW7.

* Fix issue with handling of scaling register buffer's dirty flag.

* Remove unused extern declaration.

* Compaction of struct is31_led utilizing bit fields.

drivers/issi/is31fl3741.c

@@ -97,14 +97,13 @@ bool IS31FL3741_write_pwm_buffer(uint8_t addr, uint8_t *pwm_buffer) {
     IS31FL3741_write_register(addr, ISSI_COMMANDREGISTER, ISSI_PAGE_PWM0);
 
     for (int i = 0; i < 342; i += 18) {
-        g_twi_transfer_buffer[0] = i % 180;
-
         if (i == 180) {
             // unlock the command register and select PG2
             IS31FL3741_write_register(addr, ISSI_COMMANDREGISTER_WRITELOCK, 0xC5);
             IS31FL3741_write_register(addr, ISSI_COMMANDREGISTER, ISSI_PAGE_PWM1);
         }
 
+        g_twi_transfer_buffer[0] = i % 180;
         memcpy(g_twi_transfer_buffer + 1, pwm_buffer + i, 18);
 
 #if ISSI_PERSISTENCE > 0
@@ -251,4 +250,6 @@ void IS31FL3741_set_scaling_registers(const is31_led *pled, uint8_t red, uint8_t
     g_scaling_registers[pled->driver][pled->r] = red;
     g_scaling_registers[pled->driver][pled->g] = green;
     g_scaling_registers[pled->driver][pled->b] = blue;
+
+    g_scaling_registers_update_required[pled->driver] = true;
 }

drivers/issi/is31fl3741.h

@@ -23,14 +23,13 @@
 #include <stdbool.h>
 
 typedef struct is31_led {
-    uint8_t  driver : 2;
-    uint16_t r;
-    uint16_t g;
-    uint16_t b;
+    uint32_t driver : 2;
+    uint32_t r : 10;
+    uint32_t g : 10;
+    uint32_t b : 10;
 } __attribute__((packed)) is31_led;
 
 extern const is31_led g_is31_leds[DRIVER_LED_TOTAL];
-extern const is31_led g_is31_indicator_leds[DRIVER_INDICATOR_LED_TOTAL];
 
 void IS31FL3741_init(uint8_t addr);
 void IS31FL3741_write_register(uint8_t addr, uint8_t reg, uint8_t data);