add two APIs into esp32beta.rom.spiflash.ld to fix compile error

When config flash mode as QIO mode, the error that esp_rom_spiflash_wait_idle
and esp_rom_spiflash_config_readmode are undefined happens when compile, so
add these two APIs to fix the error.

components/esp_rom/esp32s2beta/ld/esp32s2beta.rom.spiflash.ld

@@ -23,3 +23,5 @@ PROVIDE ( esp_rom_spiflash_config_clk = SPIClkConfig );
 PROVIDE ( esp_rom_spiflash_select_qio_pins = SelectSpiQIO );
 PROVIDE ( esp_rom_spiflash_unlock = SPIUnlock );
 PROVIDE ( esp_rom_spiflash_erase_sector = SPIEraseSector );
+PROVIDE ( esp_rom_spiflash_wait_idle = SPI_Wait_Idle );
+PROVIDE ( esp_rom_spiflash_config_readmode = SPIReadModeCnfig );