Remove matrix_key_count() (#16603)

* Remove `matrix_key_count()`

* Remove `matrix_bitpop()`

keyboards/bpiphany/hid_liber/matrix.c

@@ -245,15 +245,3 @@ void matrix_print(void)
         print("\n");
     }
 }
-
-uint8_t matrix_key_count(void)
-{
-    uint8_t count = 0;
-    for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-        for (uint8_t j = 0; j < MATRIX_COLS; j++) {
-            if (matrix_is_on(i, j))
-                count++;
-        }
-    }
-    return count;
-}

keyboards/bpiphany/kitten_paw/matrix.c

@@ -132,14 +132,6 @@ void matrix_print(void) {
   }
 }
 
-uint8_t matrix_key_count(void) {
-  uint8_t count = 0;
-  for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-    count += bitpop32(matrix[i]);
-  }
-  return count;
-}
-
 static uint8_t read_rows(void) {
   return
     (PINC&(1<<7) ? 0 : (1<<0)) |

keyboards/bpiphany/pegasushoof/2013/matrix.c

@@ -132,15 +132,6 @@ void matrix_print(void)
 	}
 }
 
-uint8_t matrix_key_count(void)
-{
-	uint8_t count = 0;
-	for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
-		count += bitpop16(matrix[i]);
-	}
-	return count;
-}
-
 static matrix_row_t read_cols(void)
 {
 	return

keyboards/bpiphany/pegasushoof/2015/matrix.c

@@ -111,15 +111,6 @@ void matrix_print(void)
   }
 }
 
-uint8_t matrix_key_count(void)
-{
-  uint8_t count = 0;
-  for (uint8_t i = 0; i < matrix_rows(); i++) {
-    count += bitpop16(matrix_get_row(i));
-  }
-  return count;
-}
-
 static matrix_row_t read_cols(void)
 {
   return

keyboards/bpiphany/tiger_lily/matrix.c

@@ -146,10 +146,3 @@ void matrix_print(void) {
     }
 	#endif
 }
-
-uint8_t matrix_key_count(void) {
-    uint8_t count = 0;
-    for (uint8_t row = 0; row < MATRIX_ROWS; row++)
-        count += bitpop32(matrix[row]);
-    return count;
-}

keyboards/bpiphany/unloved_bastard/matrix.c

@@ -147,10 +147,3 @@ void matrix_print(void) {
     }
 #endif
 }
-
-uint8_t matrix_key_count(void) {
-    uint8_t count = 0;
-    for (uint8_t row = 0; row < MATRIX_ROWS; row++)
-        count += bitpop32(matrix[row]);
-    return count;
-}