Remove interrupt disable around flash operations (#5577)
Remove interrupt disable around flash operations (#5577)

All interrupt service routines are supposed to be in IRAM now, so there
is no need to keep interrupts disabled while doing flash operations.
Remove the IRQ disable/enable from the ESP.flash* methods.

Related to #5568
Lan-Hekary/Arduino,Lan-Hekary/Arduino,sticilface/Arduino,esp8266/Arduino,esp8266/Arduino,esp8266/Arduino,esp8266/Arduino,Lan-Hekary/Arduino,Lan-Hekary/Arduino,Lan-Hekary/Arduino,sticilface/Arduino,sticilface/Arduino,sticilface/Arduino,sticilface/Arduino,esp8266/Arduino