esp_ringbuf: fix default placement from flash to IRAM

In earlier change this component was decoupled from freertos and hence
regression was introduced which changed default placement to flash. Some
device drivers make use of ringbuffer while flash cache is being disabled
and hence default placement should instead be internal memory.

Closes: https://github.com/espressif/esp-idf/issues/2517

components/esp32/ld/esp32.common.ld

@@ -153,6 +153,7 @@ SECTIONS
     /* Code marked as runnning out of IRAM */
     _iram_text_start = ABSOLUTE(.);
     *(.iram1 .iram1.*)
+    *libesp_ringbuf.a:(.literal .text .literal.* .text.*)
     *libfreertos.a:(.literal .text .literal.* .text.*)
     *libheap.a:multi_heap.*(.literal .text .literal.* .text.*)
     *libheap.a:multi_heap_poisoning.*(.literal .text .literal.* .text.*)