ethernet: corrected typo in ethernet/phy_ksz8051mll.c to include setting the speed to 100M in case of 100M Half Duplex
Rename rcc_ppre1_frequency and rcc_ppre2_frequency

Rename rcc_ppre1_frequency and rcc_ppre2_frequency to rcc_apb1_frequency and rcc_apb2_frequency
Also add rcc_ahb_frequency (although it is not set correctly in all cases) which will be fixed by
the rcc commits later. Also fixup the only use in the library of these variables, the USART code.

And fix the typos that resulted
Make l1 generic too
Audit RTCPRE Shift and Mask Values

L0 - RTC Prescaler appears in RCC_CR, bit 20, 2 bits wide (RM0367 Rev 2)
L1 - RTC Prescaler appears in RCC_CR, bit 29, 2 bits wide (RM0038 Rev 10)
F0 - no prescaler setting (RM0091 Rev 7)
F1 - no prescaler setting (RM0041 Rev 4)
F2 - RTC Prescaler appears at RCC_CFGR, bit 16, 4 bits wide (RM0033 Rev 6)
F3 - no prescaler setting (RM0316 Rev 3)
F4 - RTC Prescaler appears at RCC_CFGR, bit 16, 4 bits wide (RM0090 Rev 8)
stm32: f4: Add FLASH_OPTCR1 definition

This is required for stm32f42xx and stm32f43xx with second bank options.
stm32: f4: flash: support extended sector ranges

F42xx and F43xx have extended sector ranges.

Reported-by: H2OBrain@irc
stm32: f24: flash: Make code match documentation

This removes the shift from the defines, and includes them in the helper
function, making the code match the documentation, and following how the
rest of the library commonly operates.

Code using the existing defines should continue to work.