Sync with MCR20a RF driver v1.0.3

Sync with v1.0.3 in https://github.com/ARMmbed/mcr20a-rf-driver

Author: Arto Kinnunen

components/802.15.4_RF/mcr20a-rf-driver/source/NanostackRfPhyMcr20a.cpp

@@ -143,7 +143,7 @@ static const uint8_t  pll_int[16] =  {0x0B,   0x0B,   0x0B,   0x0B,   0x0B,   0x
 static const uint16_t pll_frac[16] = {0x2800, 0x5000, 0x7800, 0xA000, 0xC800, 0xF000, 0x1800, 0x4000, 0x6800, 0x9000, 0xB800, 0xE000, 0x0800, 0x3000, 0x5800, 0x8000};
 
 /* Channel configurations for 2.4 */
-static const phy_rf_channel_configuration_s phy_24ghz = {2405000000U, 5000000U, 250000U, 16U, M_OQPSK};
+static const phy_rf_channel_configuration_s phy_24ghz = {.channel_0_center_frequency = 2405000000U, .channel_spacing = 5000000U, .datarate = 250000U, .number_of_channels = 16U, .modulation = M_OQPSK};
 
 static const phy_device_channel_page_s phy_channel_pages[] = {
     { CHANNEL_PAGE_0, &phy_24ghz},