Fix inability to use all buffers in RMT (#3512)

With the >= used let's say you have four RMT inputs, each using 2 channels wide for their receive buffer. This is 4*2 = 8 buffers which is the number of hardware buffers (MAX_CHANNELS). But, for the fourth input the starting buffer will be 6 (this is correct, the buffers used for each input are 0-1, 2-3, 4-5, 6-7). But, 6+2 = 8 which  is MAX_CHANNELS. This is valid but the >= would match against it and abort. It is correct to only abort if the value i+j is only greater than MAX_CHANNELS. Thus, a simple one character fix. Delete the equals sign.

cores/esp32/esp32-hal-rmt.c

@@ -483,7 +483,7 @@ rmt_obj_t* rmtInit(int pin, bool tx_not_rx, rmt_reserve_memsize_t memsize)
             break;
         }
     }
-    if (i == MAX_CHANNELS || i+j >= MAX_CHANNELS || j != buffers)  {
+    if (i == MAX_CHANNELS || i+j > MAX_CHANNELS || j != buffers)  {
         xSemaphoreGive(g_rmt_block_lock);
         return NULL;
     }